Document
falsefalse--12-31--12-31FYFY2019201900010409710001492869Non-accelerated Filer15457000154570001247700012477000200000020000000.7750.81250.853666000003666000000.30130.30130.12870.1287108280600078368000P6MP7Y0.3330.667P3Y15702000157020001236900012369000575000017500002750000003.13753.13753.28753.28753.4353.4350.0116000000084739000802580008473900080258000P3YP3YP5Y0.04143600000577000004740000061700000P14YP1YP1YP1Y87800083400040000012000003467000004819000000.10.0290.110.07110000000205200000413100041960000.07250.060.12360.0460.0550.02751126000001695000001830000043700000625.000.010.0192000009200000920000092000009200000920000092000009200000P40YP40YP7YP3YP4Y4220000017600000214000002140000017823000178230001810600018106000140800000457100000P1YP5YP10Y50000000050000000025.0025.0061055000105500022379000223790001456200014562000The Company's consolidated balance sheets include assets and liabilities of consolidated variable interest entities ("VIEs"). See Note 2. The consolidated balance sheets include the following amounts related to our consolidated VIEs, excluding the Operating Partnership: $205.2 million and $110.0 million of land, $481.9 million and $346.7 million of building and improvements, $2.0 million and $2.0 million of building and leasehold improvements, $61.7 million and $47.4 million of right of use assets, $17.6 million and $42.2 million of accumulated depreciation, $169.5 million and $112.6 million of other assets included in other line items, $457.1 million and $140.8 million of real estate debt, net, $1.2 million and $0.4 million of accrued interest payable, $57.7 million and $43.6 million of lease liabilities, and $43.7 million and $18.3 million of other liabilities included in other line items as of December 31, 2019 and December 31, 2018, respectively.$366.6 million of the 2017 amount relates to 1515 Broadway. In November 2017, the Company sold a 30.13% interest in 1515 Broadway to affiliates of Allianz Real Estate. The sale did not meet the criteria for sale accounting and as a result the property was accounted for under the profit sharing method. The Company achieved sale accounting upon adoption of ASC 610-20 in January 2018 and closed on the sale of an additional 12.87% interest in the property to Allianz in February 2018. See Note 6, "Investments in Unconsolidated Joint Ventures.".The Operating Partnership's consolidated balance sheets include assets and liabilities of consolidated variable interest entities ("VIEs"). See Note 2. The consolidated balance sheets include the following amounts related to our consolidated VIEs, excluding the Operating Partnership: $205.2 million and $110.0 million of land, $481.9 million and $346.7 million of building and improvements, $2.0 million and $2.0 million of building and leasehold improvements, $61.7 million and $47.4 million of right of use assets, $17.6 million and $42.2 million of accumulated depreciation, $169.5 million and $112.6 million of other assets included in other line items, $457.1 million and $140.8 million of real estate debt, net, $1.2 million and $0.4 million of accrued interest payable, $57.7 million and $43.6 million of lease liabilities, and $43.7 million and $18.3 million of other liabilities included in other line items as of December 31, 2019 and December 31, 2018, respectively.$366.6 million of the 2017 amount relates to 1515 Broadway. In November 2017, the Company sold a 30.13% interest in 1515 Broadway to affiliates of Allianz Real Estate. The sale did not meet the criteria for sale accounting and as a result the property was accounted for under the profit sharing method. The Company achieved sale accounting upon adoption of ASC 610-20 in January 2018 and closed on the sale of an additional 12.87% interest in the property to Allianz in February 2018. 0001040971 2019-01-01 2019-12-31 0001040971 srt:SubsidiariesMember 2019-01-01 2019-12-31 0001040971 2019-06-30 0001040971 srt:SubsidiariesMember 2020-02-27 0001040971 2020-02-27 0001040971 us-gaap:CommonStockMember 2019-01-01 2019-12-31 0001040971 us-gaap:PreferredStockMember 2019-01-01 2019-12-31 0001040971 2018-12-31 0001040971 2019-12-31 0001040971 slg:SeriesIPreferredStockMember 2019-12-31 0001040971 srt:SubsidiariesMember us-gaap:VariableInterestEntityPrimaryBeneficiaryMember 2018-12-31 0001040971 srt:SubsidiariesMember us-gaap:VariableInterestEntityPrimaryBeneficiaryMember 2019-12-31 0001040971 slg:SeriesIPreferredStockMember 2018-12-31 0001040971 2018-01-01 2018-12-31 0001040971 2017-01-01 2017-12-31 0001040971 srt:SubsidiariesMember 2017-01-01 2017-12-31 0001040971 srt:SubsidiariesMember 2018-01-01 2018-12-31 0001040971 us-gaap:CommonStockMember 2017-12-31 0001040971 us-gaap:RetainedEarningsMember 2018-01-01 2018-12-31 0001040971 us-gaap:CommonStockMember 2018-01-01 2018-12-31 0001040971 us-gaap:AccumulatedOtherComprehensiveIncomeMember 2018-01-01 2018-12-31 0001040971 us-gaap:CommonStockMember 2019-01-01 2019-12-31 0001040971 us-gaap:CommonStockMember 2019-12-31 0001040971 us-gaap:AccumulatedOtherComprehensiveIncomeMember 2018-12-31 0001040971 us-gaap:AccountingStandardsUpdate201409Member us-gaap:RetainedEarningsMember 2018-01-01 0001040971 us-gaap:RetainedEarningsMember 2017-12-31 0001040971 us-gaap:AdditionalPaidInCapitalMember 2019-01-01 2019-12-31 0001040971 us-gaap:RetainedEarningsMember 2019-01-01 2019-12-31 0001040971 us-gaap:CommonStockMember 2018-12-31 0001040971 us-gaap:CommonStockMember 2017-01-01 2017-12-31 0001040971 us-gaap:TreasuryStockMember 2019-12-31 0001040971 us-gaap:NoncontrollingInterestMember 2017-01-01 2017-12-31 0001040971 us-gaap:AdditionalPaidInCapitalMember 2018-12-31 0001040971 slg:SeriesIPreferredStockMember us-gaap:PreferredStockMember 2018-12-31 0001040971 us-gaap:AdditionalPaidInCapitalMember 2018-01-01 2018-12-31 0001040971 us-gaap:TreasuryStockMember 2017-12-31 0001040971 slg:SeriesIPreferredStockMember us-gaap:PreferredStockMember 2016-12-31 0001040971 us-gaap:NoncontrollingInterestMember 2017-12-31 0001040971 us-gaap:AccumulatedOtherComprehensiveIncomeMember 2017-12-31 0001040971 slg:SeriesIPreferredStockMember us-gaap:PreferredStockMember 2019-12-31 0001040971 us-gaap:NoncontrollingInterestMember 2018-01-01 2018-12-31 0001040971 us-gaap:AccumulatedOtherComprehensiveIncomeMember 2019-12-31 0001040971 us-gaap:AccumulatedOtherComprehensiveIncomeMember 2016-12-31 0001040971 us-gaap:TreasuryStockMember 2018-01-01 2018-12-31 0001040971 us-gaap:AdditionalPaidInCapitalMember 2017-01-01 2017-12-31 0001040971 us-gaap:AccumulatedOtherComprehensiveIncomeMember 2019-01-01 2019-12-31 0001040971 us-gaap:AdditionalPaidInCapitalMember 2019-12-31 0001040971 us-gaap:RetainedEarningsMember 2018-12-31 0001040971 us-gaap:RetainedEarningsMember 2017-01-01 2017-12-31 0001040971 us-gaap:CommonStockMember 2016-12-31 0001040971 us-gaap:NoncontrollingInterestMember 2019-12-31 0001040971 us-gaap:TreasuryStockMember 2017-01-01 2017-12-31 0001040971 2016-12-31 0001040971 us-gaap:NoncontrollingInterestMember 2019-01-01 2019-12-31 0001040971 us-gaap:NoncontrollingInterestMember 2018-12-31 0001040971 us-gaap:AdditionalPaidInCapitalMember 2017-12-31 0001040971 us-gaap:TreasuryStockMember 2016-12-31 0001040971 us-gaap:NoncontrollingInterestMember 2016-12-31 0001040971 slg:SeriesIPreferredStockMember us-gaap:PreferredStockMember 2017-12-31 0001040971 us-gaap:RetainedEarningsMember 2019-12-31 0001040971 us-gaap:TreasuryStockMember 2018-12-31 0001040971 us-gaap:AccountingStandardsUpdate201409Member 2018-01-01 0001040971 2017-12-31 0001040971 us-gaap:AdditionalPaidInCapitalMember 2016-12-31 0001040971 us-gaap:AccumulatedOtherComprehensiveIncomeMember 2017-01-01 2017-12-31 0001040971 us-gaap:RetainedEarningsMember 2016-12-31 0001040971 us-gaap:PreferredStockMember 2018-01-01 2018-12-31 0001040971 us-gaap:PreferredStockMember 2017-01-01 2017-12-31 0001040971 slg:AllianzRealEstateMember slg:Broadway1515Member 2018-02-01 2018-02-22 0001040971 slg:AllianzRealEstateMember slg:Broadway1515Member 2017-11-01 2017-11-30 0001040971 srt:SubsidiariesMember 2018-12-31 0001040971 srt:SubsidiariesMember 2019-12-31 0001040971 us-gaap:CorporateJointVentureMember 2019-12-31 0001040971 srt:SubsidiariesMember slg:SeriesIPreferredStockMember 2019-12-31 0001040971 srt:SubsidiariesMember slg:SeriesIPreferredStockMember 2018-12-31 0001040971 srt:SubsidiariesMember us-gaap:NoncontrollingInterestMember 2018-01-01 2018-12-31 0001040971 srt:SubsidiariesMember us-gaap:NoncontrollingInterestMember 2017-12-31 0001040971 srt:SubsidiariesMember us-gaap:AccumulatedOtherComprehensiveIncomeMember 2017-12-31 0001040971 srt:SubsidiariesMember us-gaap:NoncontrollingInterestMember 2016-12-31 0001040971 srt:SubsidiariesMember us-gaap:GeneralPartnerMember us-gaap:CommonStockMember 2017-01-01 2017-12-31 0001040971 srt:SubsidiariesMember us-gaap:GeneralPartnerMember us-gaap:CommonStockMember 2019-01-01 2019-12-31 0001040971 srt:SubsidiariesMember us-gaap:NoncontrollingInterestMember 2019-01-01 2019-12-31 0001040971 srt:SubsidiariesMember us-gaap:GeneralPartnerMember us-gaap:CommonStockMember 2018-01-01 2018-12-31 0001040971 srt:SubsidiariesMember us-gaap:GeneralPartnerMember us-gaap:CommonStockMember 2019-12-31 0001040971 srt:SubsidiariesMember us-gaap:NoncontrollingInterestMember 2017-01-01 2017-12-31 0001040971 srt:SubsidiariesMember us-gaap:GeneralPartnerMember us-gaap:CommonStockMember 2016-12-31 0001040971 srt:SubsidiariesMember us-gaap:NoncontrollingInterestMember 2018-12-31 0001040971 srt:SubsidiariesMember us-gaap:AccumulatedOtherComprehensiveIncomeMember 2017-01-01 2017-12-31 0001040971 srt:SubsidiariesMember us-gaap:AccumulatedOtherComprehensiveIncomeMember 2016-12-31 0001040971 srt:SubsidiariesMember us-gaap:GeneralPartnerMember us-gaap:CommonStockMember 2017-12-31 0001040971 srt:SubsidiariesMember us-gaap:GeneralPartnerMember us-gaap:CommonStockMember 2018-12-31 0001040971 srt:SubsidiariesMember 2017-12-31 0001040971 srt:SubsidiariesMember us-gaap:AccountingStandardsUpdate201409Member 2018-01-01 0001040971 srt:SubsidiariesMember slg:SeriesIPreferredStockMember us-gaap:PreferredStockMember 2017-12-31 0001040971 srt:SubsidiariesMember us-gaap:AccumulatedOtherComprehensiveIncomeMember 2018-01-01 2018-12-31 0001040971 srt:SubsidiariesMember us-gaap:AccumulatedOtherComprehensiveIncomeMember 2018-12-31 0001040971 srt:SubsidiariesMember us-gaap:NoncontrollingInterestMember 2019-12-31 0001040971 srt:SubsidiariesMember slg:SeriesIPreferredStockMember us-gaap:PreferredStockMember 2016-12-31 0001040971 srt:SubsidiariesMember slg:SeriesIPreferredStockMember us-gaap:PreferredStockMember 2018-12-31 0001040971 srt:SubsidiariesMember 2016-12-31 0001040971 srt:SubsidiariesMember us-gaap:AccountingStandardsUpdate201409Member us-gaap:GeneralPartnerMember us-gaap:CommonStockMember 2018-01-01 0001040971 srt:SubsidiariesMember slg:SeriesIPreferredStockMember us-gaap:PreferredStockMember 2019-12-31 0001040971 srt:SubsidiariesMember us-gaap:AccumulatedOtherComprehensiveIncomeMember 2019-01-01 2019-12-31 0001040971 srt:SubsidiariesMember us-gaap:AccumulatedOtherComprehensiveIncomeMember 2019-12-31 0001040971 srt:SubsidiariesMember us-gaap:PreferredStockMember 2018-01-01 2018-12-31 0001040971 srt:SubsidiariesMember us-gaap:PreferredStockMember 2019-01-01 2019-12-31 0001040971 srt:SubsidiariesMember us-gaap:PreferredStockMember 2017-01-01 2017-12-31 0001040971 srt:SubsidiariesMember slg:AllianzRealEstateMember slg:Broadway1515Member 2017-11-01 2017-11-30 0001040971 srt:SubsidiariesMember slg:AllianzRealEstateMember slg:Broadway1515Member 2018-02-01 2018-02-22 0001040971 slg:DualPropertyTypeResidentialPortionMember slg:ManhattanMember us-gaap:ConsolidatedPropertiesMember 2019-12-31 0001040971 slg:DualPropertyTypeRetailPortionMember slg:ManhattanMember us-gaap:ConsolidatedPropertiesMember 2019-12-31 0001040971 slg:A315West33rdStreetMember us-gaap:SubsequentEventMember 2020-02-24 0001040971 slg:ManagedOfficePropertiesMember 2019-12-31 0001040971 slg:SLGreenManagementMember slg:SLGManagementLLCMember 2019-01-01 2019-12-31 0001040971 srt:PartnershipInterestMember us-gaap:VariableInterestEntityPrimaryBeneficiaryMember 2019-01-01 2019-12-31 0001040971 us-gaap:UnconsolidatedPropertiesMember 2019-12-31 0001040971 srt:RetailSiteMember slg:SuburbanMember us-gaap:ConsolidatedPropertiesMember 2019-12-31 0001040971 srt:ApartmentBuildingMember slg:ManhattanMember 2019-12-31 0001040971 srt:ApartmentBuildingMember 2019-12-31 0001040971 slg:FeeInterestMember slg:ManhattanMember us-gaap:ConsolidatedPropertiesMember 2019-12-31 0001040971 srt:OfficeBuildingMember slg:SuburbanMember us-gaap:UnconsolidatedPropertiesMember 2019-12-31 0001040971 srt:ApartmentBuildingMember us-gaap:UnconsolidatedPropertiesMember 2019-12-31 0001040971 us-gaap:ConsolidatedPropertiesMember 2019-12-31 0001040971 us-gaap:CommercialRealEstateMember us-gaap:ConsolidatedPropertiesMember 2019-12-31 0001040971 srt:ApartmentBuildingMember us-gaap:ConsolidatedPropertiesMember 2019-12-31 0001040971 slg:DevelopmentPropertiesMember slg:ManhattanMember us-gaap:ConsolidatedPropertiesMember 2019-12-31 0001040971 srt:OfficeBuildingMember slg:ManhattanMember 2019-12-31 0001040971 srt:OfficeBuildingMember slg:ManhattanMember us-gaap:ConsolidatedPropertiesMember 2019-12-31 0001040971 srt:RetailSiteMember slg:ManhattanMember us-gaap:ConsolidatedPropertiesMember 2019-12-31 0001040971 slg:ManhattanMember us-gaap:UnconsolidatedPropertiesMember 2019-12-31 0001040971 us-gaap:CommercialRealEstateMember 2019-12-31 0001040971 srt:RetailSiteMember slg:SuburbanMember us-gaap:UnconsolidatedPropertiesMember 2019-12-31 0001040971 slg:FeeInterestMember slg:ManhattanMember us-gaap:UnconsolidatedPropertiesMember 2019-12-31 0001040971 slg:ManhattanMember 2019-12-31 0001040971 slg:SuburbanMember 2019-12-31 0001040971 slg:ManhattanMember us-gaap:ConsolidatedPropertiesMember 2019-12-31 0001040971 srt:RetailSiteMember slg:ManhattanMember 2019-12-31 0001040971 srt:OfficeBuildingMember slg:ManhattanMember us-gaap:UnconsolidatedPropertiesMember 2019-12-31 0001040971 srt:OfficeBuildingMember slg:SuburbanMember 2019-12-31 0001040971 srt:RetailSiteMember slg:SuburbanMember 2019-12-31 0001040971 slg:SuburbanMember us-gaap:UnconsolidatedPropertiesMember 2019-12-31 0001040971 us-gaap:CommercialRealEstateMember us-gaap:UnconsolidatedPropertiesMember 2019-12-31 0001040971 srt:ApartmentBuildingMember slg:ManhattanMember us-gaap:UnconsolidatedPropertiesMember 2019-12-31 0001040971 srt:RetailSiteMember slg:ManhattanMember us-gaap:UnconsolidatedPropertiesMember 2019-12-31 0001040971 slg:DevelopmentPropertiesMember slg:ManhattanMember us-gaap:UnconsolidatedPropertiesMember 2019-12-31 0001040971 slg:FeeInterestMember slg:ManhattanMember 2019-12-31 0001040971 srt:ApartmentBuildingMember slg:ManhattanMember us-gaap:ConsolidatedPropertiesMember 2019-12-31 0001040971 slg:DevelopmentPropertiesMember slg:ManhattanMember 2019-12-31 0001040971 slg:SuburbanMember us-gaap:ConsolidatedPropertiesMember 2019-12-31 0001040971 srt:OfficeBuildingMember slg:SuburbanMember us-gaap:ConsolidatedPropertiesMember 2019-12-31 0001040971 us-gaap:CommercialMortgageBackedSecuritiesMember 2018-12-31 0001040971 us-gaap:CommercialMortgageBackedSecuritiesMember 2019-12-31 0001040971 us-gaap:EstimateOfFairValueFairValueDisclosureMember 2018-12-31 0001040971 us-gaap:EstimateOfFairValueFairValueDisclosureMember 2019-12-31 0001040971 slg:OtherIdentifiableAssetsMember 2019-12-31 0001040971 slg:AvenueOfTheAmericas1185Member slg:AnnualizedRentMember us-gaap:CustomerConcentrationRiskMember 2019-01-01 2019-12-31 0001040971 slg:A11MadisonAveMember slg:AnnualizedRentMember us-gaap:CustomerConcentrationRiskMember 2017-01-01 2017-12-31 0001040971 slg:Broadway1515Member slg:AnnualizedRentMember us-gaap:CustomerConcentrationRiskMember 2017-01-01 2017-12-31 0001040971 slg:A1MadisonAveMember slg:AnnualizedRentMember us-gaap:CustomerConcentrationRiskMember 2017-01-01 2017-12-31 0001040971 slg:AvenueOfTheAmericas1185Member slg:AnnualizedRentMember us-gaap:CustomerConcentrationRiskMember 2017-01-01 2017-12-31 0001040971 slg:A11MadisonAveMember slg:AnnualizedRentMember us-gaap:CustomerConcentrationRiskMember 2019-01-01 2019-12-31 0001040971 slg:East220Street42Member slg:AnnualizedRentMember us-gaap:CustomerConcentrationRiskMember 2019-01-01 2019-12-31 0001040971 slg:A1MadisonAveMember slg:AnnualizedRentMember us-gaap:CustomerConcentrationRiskMember 2018-01-01 2018-12-31 0001040971 slg:Broadway1515Member slg:AnnualizedRentMember us-gaap:CustomerConcentrationRiskMember 2019-01-01 2019-12-31 0001040971 slg:Broadway1515Member slg:AnnualizedRentMember us-gaap:CustomerConcentrationRiskMember 2018-01-01 2018-12-31 0001040971 slg:A1MadisonAveMember slg:AnnualizedRentMember us-gaap:CustomerConcentrationRiskMember 2019-01-01 2019-12-31 0001040971 slg:LexingtonAvenue420Member slg:AnnualizedRentMember us-gaap:CustomerConcentrationRiskMember 2019-01-01 2019-12-31 0001040971 slg:LexingtonAvenue420Member slg:AnnualizedRentMember us-gaap:CustomerConcentrationRiskMember 2018-01-01 2018-12-31 0001040971 slg:AvenueOfTheAmericas1185Member slg:AnnualizedRentMember us-gaap:CustomerConcentrationRiskMember 2018-01-01 2018-12-31 0001040971 slg:A11MadisonAveMember slg:AnnualizedRentMember us-gaap:CustomerConcentrationRiskMember 2018-01-01 2018-12-31 0001040971 slg:LexingtonAvenue420Member slg:AnnualizedRentMember us-gaap:CustomerConcentrationRiskMember 2017-01-01 2017-12-31 0001040971 slg:BuildingFeeOwnershipMember 2019-01-01 2019-12-31 0001040971 slg:CapitalGainsDividendMember 2017-01-01 2017-12-31 0001040971 us-gaap:WorkforceSubjectToCollectiveBargainingArrangementsMember us-gaap:LaborForceConcentrationRiskMember 2019-01-01 2019-12-31 0001040971 slg:AnnualizedRentMember us-gaap:CustomerConcentrationRiskMember 2019-12-31 0001040971 slg:OrdinaryIncomeDividendMember 2019-01-01 2019-12-31 0001040971 srt:MaximumMember slg:InPlaceLeasesMember 2019-01-01 2019-12-31 0001040971 slg:Tenant1Member slg:AnnualizedRentMember us-gaap:CustomerConcentrationRiskMember 2019-01-01 2019-12-31 0001040971 slg:AnnualizedRentMember us-gaap:CustomerConcentrationRiskMember 2019-01-01 2019-12-31 0001040971 slg:OrdinaryIncomeDividendMember 2017-01-01 2017-12-31 0001040971 us-gaap:AccountingStandardsUpdate201602Member 2019-01-01 2019-12-31 0001040971 srt:MaximumMember us-gaap:BuildingMember 2019-01-01 2019-12-31 0001040971 slg:CapitalGainsDividendMember 2018-01-01 2018-12-31 0001040971 slg:OrdinaryIncomeDividendMember 2018-01-01 2018-12-31 0001040971 srt:MaximumMember us-gaap:AboveMarketLeasesMember 2019-01-01 2019-12-31 0001040971 slg:CapitalGainsDividendMember 2019-01-01 2019-12-31 0001040971 us-gaap:EquitySecuritiesMember 2019-12-31 0001040971 slg:WorkforceSubjectToCollectiveBargainingArrangementsExpiringWithinTwoYearsMember us-gaap:LaborForceConcentrationRiskMember 2019-01-01 2019-12-31 0001040971 us-gaap:WorkforceSubjectToCollectiveBargainingArrangementsMember us-gaap:LaborForceConcentrationRiskMember 2019-12-31 0001040971 slg:CreditSuisseMember slg:AnnualizedRentMember us-gaap:CustomerConcentrationRiskMember us-gaap:SubsequentEventMember 2020-01-01 2020-01-31 0001040971 us-gaap:LeaseAgreementsMember 2019-12-31 0001040971 us-gaap:EquitySecuritiesMember 2018-12-31 0001040971 srt:MaximumMember slg:LeasesBelowMarketMember 2019-01-01 2019-12-31 0001040971 srt:MaximumMember us-gaap:FurnitureAndFixturesMember 2019-01-01 2019-12-31 0001040971 srt:MinimumMember us-gaap:BuildingMember 2019-01-01 2019-12-31 0001040971 srt:MinimumMember us-gaap:AboveMarketLeasesMember 2019-01-01 2019-12-31 0001040971 srt:MinimumMember slg:InPlaceLeasesMember 2019-01-01 2019-12-31 0001040971 srt:MinimumMember us-gaap:FurnitureAndFixturesMember 2019-01-01 2019-12-31 0001040971 srt:MaximumMember slg:BuildingLeaseholdInterestMember 2019-01-01 2019-12-31 0001040971 srt:MinimumMember slg:LeasesBelowMarketMember 2019-01-01 2019-12-31 0001040971 srt:MaximumMember slg:RightOfUseAssetsFinancingLeaseMember 2019-01-01 2019-12-31 0001040971 slg:UpperEastSideResidentialMember 2018-08-01 2018-08-31 0001040971 slg:A2HeraldSquareMember 2018-05-01 2018-05-31 0001040971 slg:UpperEastSideResidentialMember 2018-08-31 0001040971 slg:A712MadisonAvenueMember 2018-12-01 2018-12-31 0001040971 slg:A1231ThirdAvenueMember 2018-07-01 2018-07-31 0001040971 slg:A113GreeneStreetMember 2018-10-31 0001040971 slg:A712MadisonAvenueMember 2018-12-31 0001040971 slg:A113GreeneStreetMember 2018-10-01 2018-10-31 0001040971 slg:A1231ThirdAvenueMember 2018-07-31 0001040971 slg:A2HeraldSquareMember 2018-05-31 0001040971 slg:A410TenthAvenueMember 2019-05-31 0001040971 slg:A110GreeneStreetMember 2019-05-31 0001040971 slg:A2HeraldSquareMember 2018-11-01 2018-11-30 0001040971 slg:A410TenthAvenueMember 2019-05-01 2019-05-31 0001040971 slg:A110GreeneStreetMember 2019-12-31 0001040971 slg:A410TenthAvenueMember 2019-12-31 0001040971 slg:A106SpringStreetMemberMember 2019-12-31 0001040971 slg:WashingtonBoulevard1010Member 2019-11-30 0001040971 slg:A680750WashingtonBoulevardMember 2017-07-31 0001040971 slg:StevensAvenue115To117Member 2018-05-31 0001040971 slg:A600LexingtonAveMember 2018-01-01 2018-01-31 0001040971 slg:SpringStreet115Member 2019-08-31 0001040971 slg:WhitePlainsRoad520Member 2017-04-30 0001040971 slg:SummitLakeDrive400Member 2018-11-30 0001040971 slg:A1640FlatbushAvenueMember 2019-12-01 2019-12-31 0001040971 slg:A562FifthAvenueMember 2019-12-01 2019-12-31 0001040971 slg:MadisonAvenue635Member 2018-06-01 2018-06-30 0001040971 slg:A562FifthAvenueMember 2019-12-31 0001040971 slg:GreeneStreet102Member 2017-04-30 0001040971 slg:A1640FlatbushAvenueMember 2019-12-31 0001040971 slg:MadisonAvenue635Member 2018-06-30 0001040971 slg:SummitLakeDrive400Member 2018-11-01 2018-11-30 0001040971 slg:A16InternationalDriveMember 2018-07-31 0001040971 slg:Broadway1515Member 2017-12-31 0001040971 slg:UpperEastSideAssemblageMember 2018-10-01 2018-10-31 0001040971 slg:A600LexingtonAveMember 2018-01-01 0001040971 slg:A680750WashingtonBoulevardMember 2017-07-01 2017-07-31 0001040971 slg:WhitePlainsRoad520Member 2017-04-01 2017-04-30 0001040971 slg:StevensAvenue115To117Member 2018-05-01 2018-05-31 0001040971 slg:A16InternationalDriveMember 2018-07-01 2018-07-31 0001040971 slg:Broadway1515Member 2017-12-01 2017-12-31 0001040971 slg:ChubbWay125Member 2017-10-31 0001040971 slg:SuburbanMember 2019-12-31 0001040971 slg:CourtStreet16Member 2017-10-01 2017-10-31 0001040971 slg:GreeneStreet102Member 2017-04-01 2017-04-30 0001040971 slg:SuburbanMember 2019-12-01 2019-12-31 0001040971 slg:ChubbWay125Member 2017-10-01 2017-10-31 0001040971 slg:A2HeraldSquareMember 2018-11-30 0001040971 slg:CourtStreet16Member 2017-10-31 0001040971 slg:WashingtonBoulevard1010Member 2019-11-01 2019-11-30 0001040971 slg:UpperEastSideAssemblageMember 2018-10-31 0001040971 slg:SpringStreet115Member 2019-08-01 2019-08-31 0001040971 slg:GreeneStreet102Member 2017-09-01 2017-09-30 0001040971 slg:CourtStreet16Member 2017-04-30 0001040971 slg:GreeneStreet102Member 2017-04-30 0001040971 slg:Broadway1515Member 2018-02-01 2018-02-28 0001040971 slg:Broadway1515Member 2017-11-01 2017-11-30 0001040971 slg:A600LexingtonAveMember 2018-01-31 0001040971 slg:DevelopmentPropertiesMember slg:UpperEastSideAssemblageMember 2018-10-31 0001040971 slg:East220Street42Member 2019-09-30 0001040971 slg:PreferredEquityInvestmentsInMortgageLoansMember 2019-01-01 2019-12-31 0001040971 slg:MortgageMezzanineLoanWithAnInitialMaturityDueApril2021Member 2019-12-31 0001040971 us-gaap:FinancingReceivablesEqualToGreaterThan90DaysPastDueMember 2019-12-31 0001040971 slg:MezzanineLoanwithanInitialMaturityDateofJune2024Member 2019-12-31 0001040971 slg:MezzanineLoanwithanInitialMaturityDateofMarch2020Member 2019-12-31 0001040971 slg:MezzanineLoanDueDecember2029Member slg:DebtInvestmentWithFloatingInterestRateMember 2019-12-31 0001040971 slg:MezzanineLoanRepaidIn2019Member slg:DebtInvestmentWithFloatingInterestRateMember 2019-12-31 0001040971 slg:MortgageAndMezzanineLoanRepaidIn20192Member slg:DebtInvestmentWithFloatingInterestRateMember 2018-12-31 0001040971 slg:MezzanineLoanRepaidIn20198Member slg:DebtInvestmentWithFloatingInterestRateMember 2018-12-31 0001040971 slg:MezzanineLoanwithanInitialMaturityDateofJune2024Member slg:FixedRateMember 2019-12-31 0001040971 slg:MezzanineLoanRepaidIn20193Member slg:DebtInvestmentWithFloatingInterestRateMember 2019-12-31 0001040971 slg:MezzanineLoanRepaidIn20193Member slg:DebtInvestmentWithFloatingInterestRateMember 2018-12-31 0001040971 slg:MezzanineLoanwithanInitialMaturityDateofNovember2023Member slg:FixedRateMember 2018-12-31 0001040971 slg:MezzanineLoanRepaidIn20198Member slg:DebtInvestmentWithFloatingInterestRateMember 2019-12-31 0001040971 slg:MezzanineLoanwithanInitialMaturityofJuly2020Member slg:DebtInvestmentWithFloatingInterestRateMember 2019-12-31 0001040971 slg:MezzanineLoanRepaidIn20195Member slg:DebtInvestmentWithFloatingInterestRateMember 2019-12-31 0001040971 slg:JrMortgageParticipationMezzanineLoanwithanInitialMaturityofJuly2021Member slg:DebtInvestmentWithFloatingInterestRateMember 2018-12-31 0001040971 slg:MortgageMezzanineLoanDueAugust2020Member slg:DebtInvestmentWithFloatingInterestRateMember 2019-12-31 0001040971 slg:MezzanineLoanRepaidIn20192Member slg:DebtInvestmentWithFloatingInterestRateMember 2018-12-31 0001040971 slg:MortgageJr.MortgageParticipationLoanRepaidIn2019Member slg:DebtInvestmentWithFloatingInterestRateMember 2018-12-31 0001040971 slg:MezzanineLoanRepaidIn20199Member slg:DebtInvestmentWithFloatingInterestRateMember 2019-12-31 0001040971 slg:MortgageAndMezzanineLoanRepaidIn20193Member slg:DebtInvestmentWithFloatingInterestRateMember 2019-12-31 0001040971 slg:MezzanineLoanRepaidIn20196Member slg:DebtInvestmentWithFloatingInterestRateMember 2019-12-31 0001040971 slg:MortgageandMezzanineLoanwithanInitialMaturityDateofApril2020Member slg:DebtInvestmentWithFloatingInterestRateMember 2019-12-31 0001040971 slg:MezzanineLoanWithAnInitialMaturityDueJuly2021Member slg:DebtInvestmentWithFloatingInterestRateMember 2019-12-31 0001040971 slg:MortgageMezzanineLoanDueMarch2020Member slg:DebtInvestmentWithFloatingInterestRateMember 2019-12-31 0001040971 slg:MezzanineLoanWithAnInitialMaturityOfAugust2022Member slg:FixedRateMember 2019-12-31 0001040971 slg:MezzanineLoanRepaidIn20197Member slg:DebtInvestmentWithFloatingInterestRateMember 2019-12-31 0001040971 slg:MortgageMezzanineLoanWithAnInitialMaturityDueApril2021Member slg:DebtInvestmentWithFloatingInterestRateMember 2019-12-31 0001040971 slg:MezzanineLoanwithanInitialMaturityofJuly2020Member slg:DebtInvestmentWithFloatingInterestRateMember 2018-12-31 0001040971 slg:MezzanineLoanDueDecember2021Member slg:DebtInvestmentWithFloatingInterestRateMember 2018-12-31 0001040971 slg:MezzanineLoanDueSeptember2020Member slg:DebtInvestmentWithFloatingInterestRateMember 2019-12-31 0001040971 slg:MezzanineLoanRepaidIn20195Member slg:DebtInvestmentWithFloatingInterestRateMember 2018-12-31 0001040971 slg:JrMortgageParticipationMezzanineLoanwithanInitialMaturityofJuly2021Member slg:DebtInvestmentWithFloatingInterestRateMember 2019-12-31 0001040971 slg:MortgageAndMezzanineLoanRepaidIn20192Member slg:DebtInvestmentWithFloatingInterestRateMember 2019-12-31 0001040971 slg:MortgageAndMezzanineLoanWithAnInitialMaturityDateOfOctober2020Member slg:DebtInvestmentWithFloatingInterestRateMember 2018-12-31 0001040971 slg:MezzanineLoanDueDecember2022Member slg:DebtInvestmentWithFloatingInterestRateMember 2018-12-31 0001040971 slg:MezzanineLoanWithAnInitialMaturityDateOfDecember2023Member slg:FixedRateMember 2018-12-31 0001040971 slg:MezzanineLoanwithanInitialMaturityDateofMarch2020Member slg:FixedRateMember 2019-12-31 0001040971 slg:MortgageMezzanineLoanWithAnInitialMaturityDueApril2021Member slg:DebtInvestmentWithFloatingInterestRateMember 2018-12-31 0001040971 slg:MezzanineLoanwithanInitialMaturityDateofSeptember2021Member slg:FixedRateMember 2019-12-31 0001040971 slg:FixedRateMember 2019-12-31 0001040971 slg:MezzanineLoanwithanInitialMaturityDateofJune2027Member slg:FixedRateMember 2019-12-31 0001040971 slg:MezzanineLoanwithanInitialMaturityDateofJanuary2025Member slg:FixedRateMember 2019-12-31 0001040971 slg:MezzanineLoanRepaidIn20197Member slg:DebtInvestmentWithFloatingInterestRateMember 2018-12-31 0001040971 slg:MezzanineLoanRepaidIn20192Member slg:DebtInvestmentWithFloatingInterestRateMember 2019-12-31 0001040971 slg:MezzanineLoanwithanInitialMaturityDateofApril2022Member slg:FixedRateMember 2018-12-31 0001040971 slg:MortgageMezzanineLoanDueMarch2020Member slg:DebtInvestmentWithFloatingInterestRateMember 2018-12-31 0001040971 slg:MezzanineLoanwithanInitialMaturityDateofJune2024Member slg:FixedRateMember 2018-12-31 0001040971 slg:MezzanineLoanRepaidIn20199Member slg:DebtInvestmentWithFloatingInterestRateMember 2018-12-31 0001040971 slg:DebtInvestmentWithFloatingInterestRateMember 2019-12-31 0001040971 slg:MortgageAndMezzanineLoanRepaidIn2019Member slg:DebtInvestmentWithFloatingInterestRateMember 2019-12-31 0001040971 slg:MortgageMezzanineLoanwithanInitialMaturityofDecember2020Member slg:DebtInvestmentWithFloatingInterestRateMember 2019-12-31 0001040971 slg:MezzanineLoanWithMaturityJune2023Member slg:FixedRateMember 2019-12-31 0001040971 slg:MezzanineLoanSoldIn2019Member slg:FixedRateMember 2018-12-31 0001040971 slg:FixedRateMember 2018-12-31 0001040971 slg:MortgageandMezzanineLoanwithanInitialMaturityDateofApril2020Member slg:DebtInvestmentWithFloatingInterestRateMember 2018-12-31 0001040971 slg:MezzanineLoanwithanInitialMaturityDateofApril2022Member slg:FixedRateMember 2019-12-31 0001040971 slg:MezzanineLoanwithanInitialMaturityDateofNovember2023Member slg:FixedRateMember 2019-12-31 0001040971 slg:MezzanineLoanSoldIn2019Member slg:FixedRateMember 2019-12-31 0001040971 slg:MezzanineLoanwithanInitialMaturityofJanuary2020Member slg:DebtInvestmentWithFloatingInterestRateMember 2019-12-31 0001040971 slg:MezzanineLoanWithMaturityJune2023Member slg:FixedRateMember 2018-12-31 0001040971 slg:DebtInvestmentsInMortgageLoansMember 2019-12-31 0001040971 slg:MezzanineLoanDueDecember2029Member slg:DebtInvestmentWithFloatingInterestRateMember 2018-12-31 0001040971 slg:MezzanineLoanWithAnInitialMaturityDateOfDecember2023Member slg:FixedRateMember 2019-12-31 0001040971 slg:MezzanineLoanwithanInitialMaturityofJanuary2020Member slg:DebtInvestmentWithFloatingInterestRateMember 2018-12-31 0001040971 slg:MezzanineLoanDueSeptember2020Member slg:DebtInvestmentWithFloatingInterestRateMember 2018-12-31 0001040971 slg:MezzanineLoanRepaidIn20194Member slg:DebtInvestmentWithFloatingInterestRateMember 2019-12-31 0001040971 slg:MortgageAndMezzanineLoanWithAnInitialMaturityDateOfOctober2020Member slg:DebtInvestmentWithFloatingInterestRateMember 2019-12-31 0001040971 slg:MezzanineLoanDueDecember2021Member slg:DebtInvestmentWithFloatingInterestRateMember 2019-12-31 0001040971 slg:DebtInvestmentWithFloatingInterestRateMember 2018-12-31 0001040971 slg:MezzanineLoanDueDecember2022Member slg:DebtInvestmentWithFloatingInterestRateMember 2019-12-31 0001040971 slg:MortgageJr.MortgageParticipationLoanRepaidIn2019Member slg:DebtInvestmentWithFloatingInterestRateMember 2019-12-31 0001040971 slg:MezzanineLoanWithAnInitialMaturityDueApril2021Member slg:DebtInvestmentWithFloatingInterestRateMember 2019-12-31 0001040971 slg:MezzanineLoanWithAnInitialMaturityDueJuly2021Member slg:DebtInvestmentWithFloatingInterestRateMember 2018-12-31 0001040971 slg:MortgageAndMezzanineLoanRepaidIn20193Member slg:DebtInvestmentWithFloatingInterestRateMember 2018-12-31 0001040971 slg:MezzanineLoanwithanInitialMaturityDateofJanuary2025Member slg:FixedRateMember 2018-12-31 0001040971 slg:MezzanineLoanRepaidIn20196Member slg:DebtInvestmentWithFloatingInterestRateMember 2018-12-31 0001040971 slg:MortgageMezzanineLoanwithanInitialMaturityofDecember2020Member slg:DebtInvestmentWithFloatingInterestRateMember 2018-12-31 0001040971 slg:MortgageMezzanineLoanDueAugust2020Member slg:DebtInvestmentWithFloatingInterestRateMember 2018-12-31 0001040971 slg:MortgageAndMezzanineLoanRepaidIn2019Member slg:DebtInvestmentWithFloatingInterestRateMember 2018-12-31 0001040971 slg:MezzanineLoanRepaidIn2019Member slg:DebtInvestmentWithFloatingInterestRateMember 2018-12-31 0001040971 slg:MezzanineLoanRepaidIn20194Member slg:DebtInvestmentWithFloatingInterestRateMember 2018-12-31 0001040971 slg:MezzanineLoanwithanInitialMaturityDateofSeptember2021Member slg:FixedRateMember 2018-12-31 0001040971 slg:MezzanineLoanWithAnInitialMaturityOfAugust2022Member slg:FixedRateMember 2018-12-31 0001040971 slg:MezzanineLoanWithAnInitialMaturityDueApril2021Member slg:DebtInvestmentWithFloatingInterestRateMember 2018-12-31 0001040971 slg:DebtInvestmentsInMortgageLoansMember 2018-12-31 0001040971 slg:MezzanineLoanwithanInitialMaturityDateofMarch2020Member slg:FixedRateMember 2018-12-31 0001040971 slg:MezzanineLoanwithanInitialMaturityDateofJune2027Member slg:FixedRateMember 2018-12-31 0001040971 slg:DebtInvestmentsInMortgageLoansMember 2018-01-01 2018-12-31 0001040971 slg:PreferredEquityInvestmentsInMortgageLoansMember 2018-01-01 2018-12-31 0001040971 slg:PreferredEquityInvestmentsInMortgageLoansMember 2019-01-01 2019-12-31 0001040971 slg:DebtInvestmentsInMortgageLoansMember 2019-01-01 2019-12-31 0001040971 slg:PreferredEquityJune2022Member 2019-12-31 0001040971 slg:PreferredEquityInvestmentsInMortgageLoansMember 2019-12-31 0001040971 slg:PreferredEquityApril2021Member 2019-12-31 0001040971 slg:PreferredEquityInvestmentsInMortgageLoansMember 2018-12-31 0001040971 slg:PreferredEquityApril2021Member 2018-12-31 0001040971 slg:PreferredEquityJune2022Member 2018-12-31 0001040971 slg:MezzanineDebtMember slg:DebtInvestmentWithFloatingInterestRateMember 2019-12-31 0001040971 slg:SeniorMortgageMember slg:FixedRateMember 2019-12-31 0001040971 slg:PreferredEquityMember 2019-12-31 0001040971 slg:JuniorMortgageMember slg:FixedRateMember 2019-12-31 0001040971 slg:MezzanineDebtMember slg:FixedRateMember 2019-12-31 0001040971 slg:JuniorMortgageMember 2019-12-31 0001040971 slg:MezzanineDebtMember 2019-12-31 0001040971 slg:SeniorMortgageMember 2019-12-31 0001040971 slg:FixedRateMember 2019-12-31 0001040971 slg:DebtInvestmentWithFloatingInterestRateMember 2019-12-31 0001040971 slg:PreferredEquityMember slg:FixedRateMember 2019-12-31 0001040971 slg:PreferredEquityMember slg:DebtInvestmentWithFloatingInterestRateMember 2019-12-31 0001040971 slg:JuniorMortgageMember slg:DebtInvestmentWithFloatingInterestRateMember 2019-12-31 0001040971 slg:SeniorMortgageMember slg:DebtInvestmentWithFloatingInterestRateMember 2019-12-31 0001040971 slg:MezzanineDebtMember srt:MaximumMember slg:FixedRateMember 2019-12-31 0001040971 slg:PreferredEquityMember srt:MinimumMember slg:FixedRateMember 2019-12-31 0001040971 slg:JuniorMortgageMember srt:MinimumMember slg:DebtInvestmentWithFloatingInterestRateMember us-gaap:LondonInterbankOfferedRateLIBORMember 2019-12-31 0001040971 slg:SeniorMortgageMember srt:MaximumMember slg:DebtInvestmentWithFloatingInterestRateMember us-gaap:LondonInterbankOfferedRateLIBORMember 2019-12-31 0001040971 slg:MezzanineDebtMember srt:MaximumMember slg:DebtInvestmentWithFloatingInterestRateMember us-gaap:LondonInterbankOfferedRateLIBORMember 2019-12-31 0001040971 slg:MezzanineDebtMember srt:MinimumMember slg:FixedRateMember 2019-12-31 0001040971 slg:SeniorMortgageMember srt:MinimumMember slg:DebtInvestmentWithFloatingInterestRateMember us-gaap:LondonInterbankOfferedRateLIBORMember 2019-12-31 0001040971 slg:MezzanineDebtMember srt:MinimumMember slg:DebtInvestmentWithFloatingInterestRateMember us-gaap:LondonInterbankOfferedRateLIBORMember 2019-12-31 0001040971 slg:JuniorMortgageMember srt:MaximumMember slg:DebtInvestmentWithFloatingInterestRateMember us-gaap:LondonInterbankOfferedRateLIBORMember 2019-12-31 0001040971 slg:PreferredEquityMember srt:MaximumMember slg:FixedRateMember 2019-12-31 0001040971 us-gaap:CorporateJointVentureMember 2019-01-01 2019-12-31 0001040971 us-gaap:CorporateJointVentureMember 2018-01-01 2018-12-31 0001040971 us-gaap:CorporateJointVentureMember 2017-01-01 2017-12-31 0001040971 slg:East21Street66Member us-gaap:CorporateJointVentureMember 2019-12-31 0001040971 slg:GreeneStreet102Member us-gaap:CorporateJointVentureMember 2017-09-01 2017-09-30 0001040971 slg:StonehengePortfolioMember us-gaap:CorporateJointVentureMember 2019-12-31 0001040971 slg:StonehengePortfolioMember us-gaap:CorporateJointVentureMember 2017-01-01 2017-12-31 0001040971 slg:ThirdStreet175225Member us-gaap:CorporateJointVentureMember 2018-04-30 0001040971 slg:FifthAvenue724Member us-gaap:CorporateJointVentureMember 2018-07-31 0001040971 slg:Broadway1515Member us-gaap:CorporateJointVentureMember 2018-02-28 0001040971 slg:SpringStreet131To137Member us-gaap:CorporateJointVentureMember 2019-01-31 0001040971 slg:Broadway1745Member us-gaap:CorporateJointVentureMember 2018-05-31 0001040971 slg:GreeneStreet102Member us-gaap:CorporateJointVentureMember 2017-09-30 0001040971 slg:FifthAvenue521Member us-gaap:CorporateJointVentureMember 2019-05-31 0001040971 slg:ColumbusCircle3Member us-gaap:CorporateJointVentureMember 2018-11-30 0001040971 slg:MezzanineLoanMember us-gaap:CorporateJointVentureMember 2018-08-31 0001040971 slg:ColumbusCircle3Member us-gaap:CorporateJointVentureMember 2018-11-01 2018-11-30 0001040971 slg:StonehengePortfolioMember us-gaap:CorporateJointVentureMember 2019-01-01 2019-12-31 0001040971 slg:Broadway1745Member us-gaap:CorporateJointVentureMember 2018-05-01 2018-05-31 0001040971 slg:JerichoPlazaMember us-gaap:CorporateJointVentureMember 2018-06-30 0001040971 slg:A7611thAvenueMember us-gaap:CorporateJointVentureMember 2017-05-31 0001040971 slg:FifthAvenue521Member us-gaap:CorporateJointVentureMember 2019-05-01 2019-05-31 0001040971 slg:StonehengePortfolioMember us-gaap:CorporateJointVentureMember 2017-12-31 0001040971 slg:StonehengePortfolioMember us-gaap:CorporateJointVentureMember 2018-01-01 2018-12-31 0001040971 slg:ThirdStreet175225Member us-gaap:CorporateJointVentureMember 2018-04-01 2018-04-30 0001040971 slg:StonehengePortfolioMember us-gaap:CorporateJointVentureMember 2018-12-31 0001040971 slg:Broadway1515Member us-gaap:CorporateJointVentureMember 2018-02-01 2018-02-28 0001040971 slg:FifthAvenue724Member us-gaap:CorporateJointVentureMember 2018-07-01 2018-07-31 0001040971 slg:SpringStreet131To137Member us-gaap:CorporateJointVentureMember 2019-01-01 2019-01-31 0001040971 slg:JerichoPlazaMember us-gaap:CorporateJointVentureMember 2018-06-01 2018-06-30 0001040971 slg:East21Street66Member us-gaap:CorporateJointVentureMember 2019-12-01 2019-12-31 0001040971 slg:OneVanderbiltMember us-gaap:ConstructionLoansMember us-gaap:CorporateJointVentureMember 2019-01-01 2019-12-31 0001040971 slg:StonehengePropertiesMember slg:SecuredDebtInitialMaturityAugust2019Member us-gaap:CorporateJointVentureMember 2019-12-31 0001040971 slg:Broadway1552Member 2019-12-31 0001040971 slg:West46thStreet55Member us-gaap:MortgagesMember us-gaap:CorporateJointVentureMember 2019-08-31 0001040971 slg:StonehengePropertiesMember 2016-10-31 0001040971 slg:ThreeResidentialUnitsMember slg:East21Street66Member 2019-12-31 0001040971 slg:MadisonAvenue747Member 2017-05-01 2017-05-31 0001040971 slg:East400Street57Member 2016-10-01 2016-10-31 0001040971 slg:ThreeRetailandTwoResidentialUnitsMember slg:East21Street66Member 2019-12-31 0001040971 slg:ThirdAvenue919Member slg:ThirdAvenue919Member us-gaap:CorporateJointVentureMember 2019-01-01 2019-12-31 0001040971 slg:A7611thAvenueMember 2019-12-31 0001040971 slg:StonehengePropertiesMember slg:SecuredDebtInitialMaturityJune2024Member us-gaap:CorporateJointVentureMember 2019-12-31 0001040971 us-gaap:ManagementServiceBaseMember us-gaap:CorporateJointVentureMember 2018-01-01 2018-12-31 0001040971 slg:East400Street57Member 2016-10-31 0001040971 slg:StonehengePropertiesMember us-gaap:CorporateJointVentureMember 2016-10-31 0001040971 us-gaap:ManagementServiceBaseMember us-gaap:CorporateJointVentureMember 2019-01-01 2019-12-31 0001040971 slg:OneVanderbiltMember us-gaap:ConstructionLoansMember us-gaap:CorporateJointVentureMember 2019-12-31 0001040971 us-gaap:ManagementServiceBaseMember us-gaap:CorporateJointVentureMember 2017-01-01 2017-12-31 0001040971 us-gaap:CorporateJointVentureMember 2018-12-31 0001040971 slg:FifthAvenue717Member slg:MezzanineLoansOnRealEstateMember us-gaap:CorporateJointVentureMember 2018-12-31 0001040971 slg:FifthAvenue717Member slg:MezzanineLoansOnRealEstateMember us-gaap:CorporateJointVentureMember 2019-12-31 0001040971 slg:Broadway1552To1560Member us-gaap:CorporateJointVentureMember 2019-12-31 0001040971 slg:East21Street66Member us-gaap:CorporateJointVentureMember 2019-12-31 0001040971 slg:GreeneStreet121Member us-gaap:CorporateJointVentureMember 2019-12-31 0001040971 slg:A11MadisonAveMember us-gaap:CorporateJointVentureMember 2019-12-31 0001040971 slg:WorldwidePlazaMember us-gaap:CorporateJointVentureMember 2018-12-31 0001040971 slg:ParkAvenue100Member us-gaap:CorporateJointVentureMember 2019-12-31 0001040971 slg:A605West42ndStreetMember us-gaap:CorporateJointVentureMember 2019-12-31 0001040971 slg:ThirdAvenue919Member us-gaap:CorporateJointVentureMember 2019-12-31 0001040971 slg:A11MadisonAveMember us-gaap:CorporateJointVentureMember 2018-12-31 0001040971 slg:FifthAvenue717Member us-gaap:CorporateJointVentureMember 2019-12-31 0001040971 slg:StonehengePropertiesMember us-gaap:CorporateJointVentureMember 2018-12-31 0001040971 slg:A650FifthAvenueMember us-gaap:MortgagesMember us-gaap:CorporateJointVentureMember 2019-12-31 0001040971 slg:ParkAvenue280Member us-gaap:CorporateJointVentureMember 2018-12-31 0001040971 slg:East400Street57Member us-gaap:CorporateJointVentureMember 2019-12-31 0001040971 slg:ParkAvenue280Member us-gaap:CorporateJointVentureMember 2019-12-31 0001040971 slg:East53rdStreet10Member us-gaap:CorporateJointVentureMember 2019-12-31 0001040971 slg:East21Street66Member us-gaap:CorporateJointVentureMember 2018-12-31 0001040971 slg:A103East86thStreetMember us-gaap:CorporateJointVentureMember 2018-12-31 0001040971 slg:West46thStreet55Member us-gaap:CorporateJointVentureMember 2019-12-31 0001040971 slg:West11Street34Member us-gaap:CorporateJointVentureMember 2018-12-31 0001040971 slg:West11Street34Member us-gaap:CorporateJointVentureMember 2019-12-31 0001040971 slg:FifthAvenue717Member us-gaap:MortgagesMember us-gaap:CorporateJointVentureMember 2019-12-31 0001040971 slg:StonehengePropertiesMember us-gaap:CorporateJointVentureMember 2019-12-31 0001040971 slg:WorldwidePlazaMember us-gaap:CorporateJointVentureMember 2019-12-31 0001040971 slg:ThirdAvenue800Member us-gaap:CorporateJointVentureMember 2019-12-31 0001040971 slg:A103East86thStreetMember us-gaap:CorporateJointVentureMember 2019-12-31 0001040971 slg:A2HeraldSquareMember us-gaap:CorporateJointVentureMember 2019-12-31 0001040971 slg:OneVanderbiltMember us-gaap:CorporateJointVentureMember 2019-12-31 0001040971 slg:FifthAvenue717Member us-gaap:MortgagesMember us-gaap:CorporateJointVentureMember 2018-12-31 0001040971 slg:GreeneStreet121Member us-gaap:CorporateJointVentureMember 2018-12-31 0001040971 slg:A650FifthAvenueMember slg:MezzanineLoansOnRealEstateMember us-gaap:CorporateJointVentureMember 2019-12-31 0001040971 slg:ParkAvenue100Member us-gaap:CorporateJointVentureMember 2018-12-31 0001040971 slg:FifthAvenue521Member us-gaap:CorporateJointVentureMember 2018-12-31 0001040971 slg:SpringStreet115Member us-gaap:CorporateJointVentureMember 2019-12-31 0001040971 slg:West46thStreet55Member us-gaap:CorporateJointVentureMember 2018-12-31 0001040971 slg:East400Street57Member us-gaap:CorporateJointVentureMember 2018-12-31 0001040971 slg:SpringStreet131To137Member us-gaap:CorporateJointVentureMember 2018-12-31 0001040971 slg:SpringStreet115Member us-gaap:CorporateJointVentureMember 2018-12-31 0001040971 slg:A650FifthAvenueMember slg:MezzanineLoansOnRealEstateMember us-gaap:CorporateJointVentureMember 2018-12-31 0001040971 slg:A2HeraldSquareMember us-gaap:CorporateJointVentureMember 2018-12-31 0001040971 slg:Broadway1515Member us-gaap:CorporateJointVentureMember 2019-12-31 0001040971 slg:SpringStreet131To137Member us-gaap:CorporateJointVentureMember 2019-12-31 0001040971 slg:A650FifthAvenueMember us-gaap:CorporateJointVentureMember 2019-12-31 0001040971 slg:A650FifthAvenueMember us-gaap:MortgagesMember us-gaap:CorporateJointVentureMember 2018-12-31 0001040971 slg:Broadway1552To1560Member us-gaap:CorporateJointVentureMember 2018-12-31 0001040971 slg:OneVanderbiltMember us-gaap:CorporateJointVentureMember 2018-12-31 0001040971 slg:ThirdAvenue800Member us-gaap:CorporateJointVentureMember 2018-12-31 0001040971 slg:Broadway1515Member us-gaap:CorporateJointVentureMember 2018-12-31 0001040971 slg:East53rdStreet10Member us-gaap:CorporateJointVentureMember 2018-12-31 0001040971 slg:ThirdAvenue919Member us-gaap:CorporateJointVentureMember 2018-12-31 0001040971 slg:A605West42ndStreetMember us-gaap:CorporateJointVentureMember 2018-12-31 0001040971 slg:FifthAvenue521Member us-gaap:CorporateJointVentureMember 2019-12-31 0001040971 slg:MezzanineLoansAndPreferredEquityMember 2019-12-31 0001040971 slg:ParticipatingFinancingDueFebruary2022Member 2018-12-31 0001040971 slg:MezzanineLoansAndPreferredEquityMember 2018-12-31 0001040971 slg:ParticipatingFinancingDueFebruary2022Member 2019-12-31 0001040971 slg:A333East22ndStMember us-gaap:CorporateJointVentureMember 2019-12-31 0001040971 slg:A185BroadwayMember us-gaap:ConstructionLoansMember 2019-12-31 0001040971 slg:Amsterdam1080Member 2019-12-31 0001040971 srt:WeightedAverageMember slg:Amsterdam1080Member 2019-01-01 2019-12-31 0001040971 srt:WeightedAverageMember slg:Amsterdam1080Member us-gaap:SeniorSubordinatedLoansMember 2019-12-31 0001040971 slg:A410TenthAvenueMember us-gaap:ConstructionLoansMember 2019-01-01 2019-12-31 0001040971 slg:FHLBFacilityFebruary2020Member us-gaap:SubsequentEventMember 2020-02-01 2020-02-24 0001040971 slg:FHLBFacilityJanuary2020Member us-gaap:SubsequentEventMember 2020-01-01 2020-01-31 0001040971 slg:A460West34thStreetMember us-gaap:ConstructionLoansMember 2019-01-01 2019-12-31 0001040971 slg:UncommittedMasterRepurchaseAgreement2017Member 2019-12-31 0001040971 slg:UncommittedMasterRepurchaseAgreement2017Member 2019-08-01 2019-08-31 0001040971 slg:SpringStreet115Member 2019-01-01 2019-12-31 0001040971 slg:FHLBFacilityJanuary2020Member us-gaap:SubsequentEventMember 2020-01-31 0001040971 slg:A185BroadwayMember us-gaap:ConstructionLoansMember 2019-01-01 2019-12-31 0001040971 slg:UncommittedMasterRepurchaseAgreement2017Member 2019-06-01 2019-06-30 0001040971 slg:A410TenthAvenueMember us-gaap:ConstructionLoansMember 2019-12-31 0001040971 slg:FHLBFacilityFebruary2020Member us-gaap:SubsequentEventMember 2020-02-24 0001040971 srt:WeightedAverageMember slg:East400Street58Member 2019-01-01 2019-12-31 0001040971 slg:TiconderogaInsuranceCompanyMember slg:LIBORPlus25BasisPointsMember 2019-12-31 0001040971 slg:UncommittedMasterRepurchaseAgreement2017Member 2018-06-01 2018-06-30 0001040971 srt:WeightedAverageMember slg:East400Street58Member 2019-12-31 0001040971 slg:TiconderogaInsuranceCompanyMember slg:LIBORPlus25BasisPointsMember us-gaap:LondonInterbankOfferedRateLIBORMember 2019-01-01 2019-12-31 0001040971 slg:UncommittedMasterRepurchaseAgreement2017Member 2018-04-30 0001040971 srt:WeightedAverageMember slg:Amsterdam1080Member us-gaap:MortgagesMember 2019-12-31 0001040971 srt:WeightedAverageMember slg:MadisonAvenue762Member 2019-12-31 0001040971 slg:MadisonAvenue762Member 2018-12-31 0001040971 slg:FifthAvenue609Member 2018-12-31 0001040971 srt:WeightedAverageMember slg:UncommittedMasterRepurchaseAgreement2017Member 2019-12-31 0001040971 srt:WeightedAverageMember slg:A315West33rdStreetMember 2019-12-31 0001040971 srt:WeightedAverageMember slg:AmsterdamAvenue1080Member 2019-12-31 0001040971 srt:WeightedAverageMember slg:LexingtonAvenue485Member 2019-12-31 0001040971 slg:LexingtonAvenue485Member 2018-12-31 0001040971 slg:East400Street58Member 2018-12-31 0001040971 srt:WeightedAverageMember slg:LandmarkSquareMember 2019-12-31 0001040971 slg:A185BroadwayMember 2019-12-31 0001040971 slg:A133GreeneStreetMember 2019-12-31 0001040971 slg:A133GreeneStreetMember 2018-12-31 0001040971 slg:AmsterdamAvenue1080Member 2019-12-31 0001040971 slg:A185BroadwayMember 2018-12-31 0001040971 slg:UncommittedMasterRepurchaseAgreement2017Member 2018-12-31 0001040971 slg:A106SpringStreetMemberMember 2019-12-31 0001040971 slg:FHLBFacilityJanuary2020Member 2018-12-31 0001040971 slg:FHLBFacilityJune2020Member 2018-12-31 0001040971 slg:East400Street58Member 2019-12-31 0001040971 slg:A315West33rdStreetMember 2019-12-31 0001040971 slg:FHLBFacilityFebruary2020Member 2018-12-31 0001040971 srt:WeightedAverageMember slg:LexingtonAvenue420Member 2019-12-31 0001040971 srt:WeightedAverageMember slg:A410TenthAvenueMember 2019-12-31 0001040971 srt:WeightedAverageMember slg:ChurchStreet100Member 2019-12-31 0001040971 slg:FHLBFacilityJune2020Member 2019-12-31 0001040971 srt:WeightedAverageMember slg:SevenOneNineSeventhAvenueMember 2019-12-31 0001040971 srt:WeightedAverageMember slg:A712MadisonAvenueMember 2019-12-31 0001040971 srt:WeightedAverageMember slg:FHLBFacilityJune2020Member 2019-12-31 0001040971 slg:FHLBFacilityDecember2019Member 2018-12-31 0001040971 slg:LexingtonAvenue420Member 2018-12-31 0001040971 srt:WeightedAverageMember slg:FHLBFacilityFebruary2020Member 2019-12-31 0001040971 srt:WeightedAverageMember slg:A106SpringStreetMemberMember 2019-12-31 0001040971 slg:A106SpringStreetMemberMember 2018-12-31 0001040971 slg:ChurchStreet100Member 2019-12-31 0001040971 slg:SevenOneNineSeventhAvenueMember 2019-12-31 0001040971 slg:A410TenthAvenueMember 2019-12-31 0001040971 srt:WeightedAverageMember slg:A185BroadwayMember 2019-12-31 0001040971 slg:FHLBFacilityAugust2019Member 2018-12-31 0001040971 srt:WeightedAverageMember slg:A133GreeneStreetMember 2019-12-31 0001040971 slg:LandmarkSquareMember 2019-12-31 0001040971 slg:A712MadisonAvenueMember 2018-12-31 0001040971 srt:WeightedAverageMember slg:FifthAvenue609Member 2019-12-31 0001040971 srt:WeightedAverageMember slg:FHLBFacilityJanuary2020Member 2019-12-31 0001040971 slg:FHLBFacilityJanuary2020Member 2019-12-31 0001040971 slg:SpringStreet115Member 2018-12-31 0001040971 slg:LexingtonAvenue485Member 2019-12-31 0001040971 slg:A712MadisonAvenueMember 2019-12-31 0001040971 slg:LandmarkSquareMember 2018-12-31 0001040971 slg:ChurchStreet100Member 2018-12-31 0001040971 slg:FHLBFacilityFebruary2020Member 2019-12-31 0001040971 slg:FifthAvenue609Member 2019-12-31 0001040971 slg:A410TenthAvenueMember 2018-12-31 0001040971 slg:LexingtonAvenue420Member 2019-12-31 0001040971 slg:A315West33rdStreetMember 2018-12-31 0001040971 slg:AmsterdamAvenue1080Member 2018-12-31 0001040971 slg:MadisonAvenue762Member 2019-12-31 0001040971 slg:SevenOneNineSeventhAvenueMember 2018-12-31 0001040971 slg:CreditFacility2017Member 2019-12-31 0001040971 srt:MaximumMember us-gaap:RevolvingCreditFacilityMember 2019-01-01 2019-12-31 0001040971 slg:CreditFacility2017Member us-gaap:LineOfCreditMember 2019-12-31 0001040971 srt:MinimumMember slg:TermLoanAMaturityMarch312023Member slg:TermLoanMember us-gaap:LondonInterbankOfferedRateLIBORMember 2019-01-01 2019-12-31 0001040971 us-gaap:RevolvingCreditFacilityMember 2019-12-31 0001040971 us-gaap:JuniorSubordinatedDebtMember us-gaap:LondonInterbankOfferedRateLIBORMember 2019-01-01 2019-12-31 0001040971 slg:TermLoanMember us-gaap:LineOfCreditMember 2019-12-31 0001040971 us-gaap:RevolvingCreditFacilityMember slg:RevolvingCreditFacilityMaturityMarch312022Member us-gaap:LineOfCreditMember us-gaap:LondonInterbankOfferedRateLIBORMember 2019-01-01 2019-12-31 0001040971 slg:SeniorUnsecuredNotesDueAugust2021Member slg:SeniorUnsecuredNotesMember 2019-01-01 2019-12-31 0001040971 srt:MaximumMember slg:TermLoanAMaturityMarch312023Member slg:TermLoanMember us-gaap:LondonInterbankOfferedRateLIBORMember 2019-01-01 2019-12-31 0001040971 us-gaap:RevolvingCreditFacilityMember slg:RevolvingCreditFacilityMaturityMarch312022Member us-gaap:LineOfCreditMember 2019-12-31 0001040971 srt:MaximumMember us-gaap:RevolvingCreditFacilityMember slg:RevolvingCreditFacilityMaturityMarch312022Member us-gaap:LineOfCreditMember us-gaap:LondonInterbankOfferedRateLIBORMember 2019-01-01 2019-12-31 0001040971 srt:MinimumMember slg:TermLoanBMaturityNovember212024Member slg:TermLoanMember us-gaap:LondonInterbankOfferedRateLIBORMember 2019-01-01 2019-12-31 0001040971 slg:A4.50PercentSeniorUnsecuredBondsDueDecember2022Member slg:SeniorUnsecuredBondsMember 2017-10-31 0001040971 slg:TermLoanBMaturityNovember212024Member us-gaap:LondonInterbankOfferedRateLIBORMember 2019-05-01 2019-05-31 0001040971 srt:MinimumMember slg:TermLoanBMaturityNovember212024Member us-gaap:LondonInterbankOfferedRateLIBORMember 2019-05-01 2019-05-31 0001040971 srt:MaximumMember slg:TermLoanBMaturityNovember212024Member us-gaap:LondonInterbankOfferedRateLIBORMember 2019-05-01 2019-05-31 0001040971 srt:MaximumMember slg:TermLoanBMaturityNovember212024Member slg:TermLoanMember us-gaap:LondonInterbankOfferedRateLIBORMember 2019-01-01 2019-12-31 0001040971 us-gaap:RevolvingCreditFacilityMember 2019-01-01 2019-12-31 0001040971 slg:TermLoanAMaturityMarch312023Member slg:TermLoanMember 2019-12-31 0001040971 slg:A4.50PercentSeniorUnsecuredBondsDueDecember2022Member slg:SeniorUnsecuredBondsMember 2017-10-01 2017-10-31 0001040971 slg:TermLoanBMaturityNovember212024Member slg:TermLoanMember 2019-12-31 0001040971 us-gaap:JuniorSubordinatedDebtMember 2005-06-01 2005-06-30 0001040971 srt:MinimumMember us-gaap:RevolvingCreditFacilityMember slg:RevolvingCreditFacilityMaturityMarch312022Member us-gaap:LineOfCreditMember us-gaap:LondonInterbankOfferedRateLIBORMember 2019-01-01 2019-12-31 0001040971 slg:TermLoanMember us-gaap:LineOfCreditMember 2018-12-31 0001040971 slg:CreditFacility2017Member us-gaap:LineOfCreditMember 2018-12-31 0001040971 slg:TermLoanAMaturityMarch312023Member slg:TermLoanMember us-gaap:LondonInterbankOfferedRateLIBORMember 2019-01-01 2019-12-31 0001040971 slg:TermLoanBMaturityNovember212024Member slg:TermLoanMember us-gaap:LondonInterbankOfferedRateLIBORMember 2019-01-01 2019-12-31 0001040971 srt:MinimumMember us-gaap:RevolvingCreditFacilityMember 2019-01-01 2019-12-31 0001040971 slg:MortgageAndOtherLoansPayableMember us-gaap:CorporateJointVentureMember 2019-12-31 0001040971 slg:TermLoanMember us-gaap:CorporateJointVentureMember 2019-12-31 0001040971 us-gaap:JuniorSubordinatedDebtMember us-gaap:CorporateJointVentureMember 2019-12-31 0001040971 slg:CreditFacility2012Member us-gaap:CorporateJointVentureMember 2019-12-31 0001040971 us-gaap:SeniorNotesMember us-gaap:CorporateJointVentureMember 2019-12-31 0001040971 slg:SeniorUnsecuredNoteDueDecember172025Member slg:SeniorUnsecuredNotesMember 2019-01-01 2019-12-31 0001040971 slg:SeniorUnsecuredNotesMember 2019-12-31 0001040971 slg:SeniorUnsecuredNotesDueDecember12022Member slg:SeniorUnsecuredNotesMember 2019-12-31 0001040971 slg:SeniorUnsecuredNoteDueDecember172025Member slg:SeniorUnsecuredNotesMember 2019-12-31 0001040971 slg:SeniorUnsecuredNotesDueAugust2021Member slg:SeniorUnsecuredNotesMember 2019-12-31 0001040971 slg:SeniorUnsecuredNotesDueMarch152020Member slg:SeniorUnsecuredNotesMember 2019-12-31 0001040971 slg:SeniorUnsecuredNotesDueDecember12022Member slg:SeniorUnsecuredNotesMember 2018-12-31 0001040971 slg:A3.25PercentSeniorUnsecuredNotesDueOctober2022Member slg:SeniorUnsecuredNotesMember 2018-12-31 0001040971 slg:A3.25PercentSeniorUnsecuredNotesDueOctober2022Member slg:SeniorUnsecuredNotesMember 2019-12-31 0001040971 slg:SeniorUnsecuredNoteDueDecember172025Member slg:SeniorUnsecuredNotesMember 2018-12-31 0001040971 slg:SeniorUnsecuredNotesDueMarch152020Member slg:SeniorUnsecuredNotesMember 2019-01-01 2019-12-31 0001040971 slg:SeniorUnsecuredNotesMember 2018-12-31 0001040971 slg:SeniorUnsecuredNotesDueMarch152020Member slg:SeniorUnsecuredNotesMember 2018-12-31 0001040971 slg:SeniorUnsecuredNotesDueDecember12022Member slg:SeniorUnsecuredNotesMember 2019-01-01 2019-12-31 0001040971 slg:A3.25PercentSeniorUnsecuredNotesDueOctober2022Member slg:SeniorUnsecuredNotesMember 2019-01-01 2019-12-31 0001040971 slg:SeniorUnsecuredNotesDueAugust2021Member slg:SeniorUnsecuredNotesMember 2018-12-31 0001040971 us-gaap:RevolvingCreditFacilityMember slg:RevolvingCreditFacilityMaturityMarch312022Member us-gaap:LineOfCreditMember 2019-01-01 2019-12-31 0001040971 slg:RelatedPartyStephenLGreenInterestMember srt:AffiliatedEntityMember 2018-01-01 2018-12-31 0001040971 slg:RelatedPartyStephenLGreenInterestMember srt:AffiliatedEntityMember 2019-01-01 2019-12-31 0001040971 slg:AllianceBuildingServicesMember srt:AffiliatedEntityMember 2018-01-01 2018-12-31 0001040971 slg:MarcHollidayChairmanAndCEOMember srt:MaximumMember slg:OneVanderbiltMember srt:AffiliatedEntityMember 2016-12-01 2016-12-31 0001040971 slg:HolidayAndMathiasMember slg:OneVanderbiltMember srt:AffiliatedEntityMember 2019-01-01 2019-12-31 0001040971 slg:AndrewMathiasPresidentMember srt:MinimumMember slg:OneVanderbiltMember srt:AffiliatedEntityMember 2016-12-01 2016-12-31 0001040971 slg:AllianceBuildingServicesMember srt:AffiliatedEntityMember 2017-01-01 2017-12-31 0001040971 slg:AndrewMathiasPresidentMember slg:OneVanderbiltMember srt:AffiliatedEntityMember 2016-12-31 0001040971 slg:AllianceBuildingServicesMember srt:AffiliatedEntityMember 2019-01-01 2019-12-31 0001040971 slg:MarcHollidayChairmanAndCEOMember slg:OneVanderbiltMember srt:AffiliatedEntityMember 2016-12-31 0001040971 slg:MarcHollidayChairmanAndCEOMember srt:MinimumMember slg:OneVanderbiltMember srt:AffiliatedEntityMember 2016-12-01 2016-12-31 0001040971 slg:RelatedPartyStephenLGreenInterestMember srt:AffiliatedEntityMember 2017-01-01 2017-12-31 0001040971 slg:AndrewMathiasPresidentMember srt:MaximumMember slg:OneVanderbiltMember srt:AffiliatedEntityMember 2016-12-01 2016-12-31 0001040971 srt:SubsidiariesMember slg:SeriesLPreferredStockMember 2019-12-31 0001040971 srt:SubsidiariesMember slg:SeriesPPreferredStockMember 2019-01-01 2019-12-31 0001040971 srt:SubsidiariesMember us-gaap:SeriesGPreferredStockMember 2019-12-31 0001040971 srt:SubsidiariesMember slg:SeriesUPreferredStockMember 2019-12-31 0001040971 srt:SubsidiariesMember slg:SeriesTPreferredStockMemberMember 2019-12-31 0001040971 srt:SubsidiariesMember slg:SeriesOPreferredStockMember 2019-01-01 2019-12-31 0001040971 srt:SubsidiariesMember slg:SeriesQPreferredStockMember 2019-12-31 0001040971 srt:SubsidiariesMember slg:SeriesPPreferredStockMember 2019-12-31 0001040971 srt:SubsidiariesMember us-gaap:SeriesFPreferredStockMember 2019-12-31 0001040971 srt:SubsidiariesMember slg:SeriesVPreferredStockMember 2019-12-31 0001040971 srt:SubsidiariesMember slg:SeriesMPreferredStockMember 2019-01-01 2019-12-31 0001040971 srt:SubsidiariesMember slg:SeriesSPreferredStockMember 2019-12-31 0001040971 srt:SubsidiariesMember slg:SeriesSPreferredStockMember 2019-01-01 2019-12-31 0001040971 srt:SubsidiariesMember slg:SeriesOPreferredStockMember 2019-12-31 0001040971 srt:SubsidiariesMember us-gaap:SeriesGPreferredStockMember 2019-01-01 2019-12-31 0001040971 srt:SubsidiariesMember slg:SeriesRPreferredStockMember 2019-12-31 0001040971 srt:SubsidiariesMember slg:SeriesUPreferredStockMember 2019-01-01 2019-12-31 0001040971 srt:SubsidiariesMember slg:SeriesRPreferredStockMember 2019-01-01 2019-12-31 0001040971 srt:SubsidiariesMember us-gaap:SeriesAPreferredStockMember 2019-12-31 0001040971 srt:SubsidiariesMember us-gaap:SeriesAPreferredStockMember 2019-01-01 2019-12-31 0001040971 srt:SubsidiariesMember slg:SeriesMPreferredStockMember 2019-12-31 0001040971 srt:SubsidiariesMember slg:SeriesLPreferredStockMember 2019-01-01 2019-12-31 0001040971 srt:SubsidiariesMember slg:SeriesTPreferredStockMemberMember 2019-01-01 2019-12-31 0001040971 srt:SubsidiariesMember slg:SeriesKPreferredStockMember 2019-12-31 0001040971 srt:SubsidiariesMember slg:SeriesNPreferredStockMember 2019-01-01 2019-12-31 0001040971 srt:SubsidiariesMember slg:SeriesNPreferredStockMember 2019-12-31 0001040971 srt:SubsidiariesMember us-gaap:SeriesFPreferredStockMember 2019-01-01 2019-12-31 0001040971 srt:SubsidiariesMember slg:SeriesKPreferredStockMember 2019-01-01 2019-12-31 0001040971 srt:SubsidiariesMember slg:SeriesQPreferredStockMember 2019-01-01 2019-12-31 0001040971 srt:SubsidiariesMember slg:SeriesVPreferredStockMember 2019-01-01 2019-12-31 0001040971 srt:PartnershipInterestMember 2019-01-01 2019-12-31 0001040971 srt:PartnershipInterestMember 2018-01-01 2018-12-31 0001040971 srt:PartnershipInterestMember 2018-12-31 0001040971 srt:PartnershipInterestMember 2017-12-31 0001040971 srt:PartnershipInterestMember 2019-12-31 0001040971 us-gaap:SeriesBPreferredStockMember 2019-12-31 0001040971 srt:SubsidiariesMember srt:MinimumMember us-gaap:SeriesAPreferredStockMember 2019-01-01 2019-12-31 0001040971 srt:PartnershipInterestMember us-gaap:PreferredStockMember 2018-01-01 2018-12-31 0001040971 srt:PartnershipInterestMember us-gaap:PreferredStockMember 2018-12-31 0001040971 srt:PartnershipInterestMember us-gaap:PreferredStockMember 2019-01-01 2019-12-31 0001040971 srt:PartnershipInterestMember us-gaap:PreferredStockMember 2019-12-31 0001040971 srt:PartnershipInterestMember us-gaap:PreferredStockMember 2017-12-31 0001040971 slg:A2016RepurchaseProgramMember 2017-01-01 2017-12-31 0001040971 slg:A2016RepurchaseProgramMember 2019-01-01 2019-12-31 0001040971 slg:A2016RepurchaseProgramMember 2018-01-01 2018-12-31 0001040971 slg:DividendReinvestmentAndStockPurchasePlanMember 2018-02-28 0001040971 slg:A2016RepurchaseProgramMember 2019-12-31 0001040971 slg:A2015ATMEquityOfferingProgramMember 2015-03-31 0001040971 slg:SeriesIPreferredStockMember 2012-08-01 2012-08-31 0001040971 slg:A2016RepurchaseProgramMember 2016-08-31 0001040971 srt:SubsidiariesMember us-gaap:CommonStockMember 2019-12-31 0001040971 slg:A2016RepurchaseProgramMember 2017-12-31 0001040971 slg:SeriesIPreferredStockMember 2019-01-01 2019-12-31 0001040971 slg:SeriesIPreferredStockMember 2012-08-31 0001040971 slg:DividendReinvestmentAndStockPurchasePlanMember 2018-01-01 2018-12-31 0001040971 slg:DividendReinvestmentAndStockPurchasePlanMember 2017-01-01 2017-12-31 0001040971 slg:DividendReinvestmentAndStockPurchasePlanMember 2019-01-01 2019-12-31 0001040971 slg:A2016RepurchaseProgramMember 2018-12-31 0001040971 slg:A2016RepurchaseProgramMember 2018-06-30 0001040971 srt:SubsidiariesMember slg:SeriesIPreferredStockMember 2019-01-01 2019-12-31 0001040971 us-gaap:EmployeeStockOptionMember 2019-12-31 0001040971 us-gaap:EmployeeStockOptionMember 2018-12-31 0001040971 us-gaap:EmployeeStockOptionMember 2017-12-31 0001040971 us-gaap:EmployeeStockOptionMember 2019-01-01 2019-12-31 0001040971 us-gaap:EmployeeStockOptionMember 2018-01-01 2018-12-31 0001040971 us-gaap:EmployeeStockOptionMember 2017-01-01 2017-12-31 0001040971 us-gaap:EmployeeStockOptionMember 2016-12-31 0001040971 us-gaap:RestrictedStockMember 2018-01-01 2018-12-31 0001040971 us-gaap:RestrictedStockMember 2018-12-31 0001040971 us-gaap:RestrictedStockMember 2019-01-01 2019-12-31 0001040971 us-gaap:RestrictedStockMember 2017-01-01 2017-12-31 0001040971 us-gaap:RestrictedStockMember 2017-12-31 0001040971 us-gaap:RestrictedStockMember 2016-12-31 0001040971 us-gaap:RestrictedStockMember 2019-12-31 0001040971 slg:FourthAmendedandRestated2003StockOptionandIncentivePlanMember 2019-12-31 0001040971 srt:MaximumMember us-gaap:EmployeeStockOptionMember 2019-01-01 2019-12-31 0001040971 slg:RestrictedStockAwardsMember 2019-01-01 2019-12-31 0001040971 slg:LongTermOutperformanceCompensationProgram2014Member 2019-01-01 2019-12-31 0001040971 us-gaap:PerformanceSharesMember 2019-01-01 2019-12-31 0001040971 us-gaap:EmployeeStockMember 2019-01-01 2019-12-31 0001040971 us-gaap:EmployeeStockOptionMember slg:ThirdAmendmentandRestated2005StockOptionandIncentivePlanMember 2019-01-01 2019-12-31 0001040971 us-gaap:EmployeeStockMember 2019-12-31 0001040971 slg:LongTermOutperformanceCompensationProgram2014Member slg:SharebasedCompensationAwardTrancheFourMember 2018-08-31 2018-08-31 0001040971 slg:LongTermIncentivePlanUnitsMember 2018-01-01 2018-12-31 0001040971 slg:LongTermOutperformanceCompensationProgram2014Member 2017-01-01 2017-12-31 0001040971 us-gaap:PerformanceSharesMember 2019-12-31 0001040971 us-gaap:EmployeeStockOptionMember slg:ThirdAmendmentandRestated2005StockOptionandIncentivePlanMember 2018-01-01 2018-12-31 0001040971 us-gaap:PerformanceSharesMember 2018-01-01 2018-12-31 0001040971 slg:DeferredStockCompensationPlanForDirectorsMember 2019-01-01 2019-12-31 0001040971 us-gaap:PerformanceSharesMember 2017-01-01 2017-12-31 0001040971 slg:LongTermOutperformanceCompensationProgram2014Member 2014-08-01 2014-08-31 0001040971 slg:StockOptionsStockAppreciationRightsAndOtherAwardsMember 2019-12-31 0001040971 slg:LongTermIncentivePlanUnitsMember 2019-01-01 2019-12-31 0001040971 slg:LongTermOutperformanceCompensationProgram2014Member us-gaap:ShareBasedCompensationAwardTrancheThreeMember 2017-08-31 2017-08-31 0001040971 slg:DeferredStockCompensationPlanForDirectorsMember 2019-12-31 0001040971 slg:OtherAwardsMember 2019-12-31 0001040971 slg:ClassOLTIPUnitsMember 2019-12-31 0001040971 us-gaap:EmployeeStockOptionMember slg:ThirdAmendmentandRestated2005StockOptionandIncentivePlanMember 2017-01-01 2017-12-31 0001040971 slg:StockOptionsStockAppreciationRightsAndOtherAwardsMember 2019-01-01 2019-12-31 0001040971 slg:LongTermOutperformanceCompensationProgram2014Member 2014-08-31 0001040971 srt:MinimumMember us-gaap:EmployeeStockOptionMember 2019-01-01 2019-12-31 0001040971 slg:OtherAwardsMember 2019-01-01 2019-12-31 0001040971 us-gaap:AccumulatedGainLossCashFlowHedgeIncludingNoncontrollingInterestMember 2017-01-01 2017-12-31 0001040971 us-gaap:AccumulatedNetInvestmentGainLossIncludingPortionAttributableToNoncontrollingInterestMember 2016-12-31 0001040971 us-gaap:AccumulatedGainLossCashFlowHedgeIncludingNoncontrollingInterestMember 2018-01-01 2018-12-31 0001040971 us-gaap:AociIncludingPortionAttributableToNoncontrollingInterestMember 2016-12-31 0001040971 us-gaap:CorporateJointVentureMember us-gaap:AccumulatedGainLossCashFlowHedgeIncludingNoncontrollingInterestMember 2016-12-31 0001040971 us-gaap:AccumulatedNetInvestmentGainLossIncludingPortionAttributableToNoncontrollingInterestMember 2019-12-31 0001040971 us-gaap:CorporateJointVentureMember us-gaap:AccumulatedGainLossCashFlowHedgeIncludingNoncontrollingInterestMember 2017-01-01 2017-12-31 0001040971 us-gaap:AccumulatedNetInvestmentGainLossIncludingPortionAttributableToNoncontrollingInterestMember 2019-01-01 2019-12-31 0001040971 us-gaap:CorporateJointVentureMember us-gaap:AccumulatedGainLossCashFlowHedgeIncludingNoncontrollingInterestMember 2018-01-01 2018-12-31 0001040971 us-gaap:AccumulatedNetInvestmentGainLossIncludingPortionAttributableToNoncontrollingInterestMember 2018-01-01 2018-12-31 0001040971 us-gaap:AccumulatedNetInvestmentGainLossIncludingPortionAttributableToNoncontrollingInterestMember 2018-12-31 0001040971 us-gaap:AccumulatedGainLossCashFlowHedgeIncludingNoncontrollingInterestMember 2017-12-31 0001040971 us-gaap:AccumulatedGainLossCashFlowHedgeIncludingNoncontrollingInterestMember 2018-12-31 0001040971 us-gaap:AociIncludingPortionAttributableToNoncontrollingInterestMember 2018-12-31 0001040971 us-gaap:AociIncludingPortionAttributableToNoncontrollingInterestMember 2017-12-31 0001040971 us-gaap:CorporateJointVentureMember us-gaap:AccumulatedGainLossCashFlowHedgeIncludingNoncontrollingInterestMember 2019-01-01 2019-12-31 0001040971 us-gaap:AccumulatedGainLossCashFlowHedgeIncludingNoncontrollingInterestMember 2016-12-31 0001040971 us-gaap:AccumulatedNetInvestmentGainLossIncludingPortionAttributableToNoncontrollingInterestMember 2017-12-31 0001040971 us-gaap:AociIncludingPortionAttributableToNoncontrollingInterestMember 2019-12-31 0001040971 us-gaap:AccumulatedGainLossCashFlowHedgeIncludingNoncontrollingInterestMember 2019-01-01 2019-12-31 0001040971 us-gaap:CorporateJointVentureMember us-gaap:AccumulatedGainLossCashFlowHedgeIncludingNoncontrollingInterestMember 2019-12-31 0001040971 us-gaap:AccumulatedNetInvestmentGainLossIncludingPortionAttributableToNoncontrollingInterestMember 2017-01-01 2017-12-31 0001040971 us-gaap:AccumulatedGainLossCashFlowHedgeIncludingNoncontrollingInterestMember 2019-12-31 0001040971 us-gaap:CorporateJointVentureMember us-gaap:AccumulatedGainLossCashFlowHedgeIncludingNoncontrollingInterestMember 2018-12-31 0001040971 us-gaap:CorporateJointVentureMember us-gaap:AccumulatedGainLossCashFlowHedgeIncludingNoncontrollingInterestMember 2017-12-31 0001040971 us-gaap:FairValueInputsLevel3Member us-gaap:EstimateOfFairValueFairValueDisclosureMember 2019-12-31 0001040971 us-gaap:CarryingReportedAmountFairValueDisclosureMember 2018-12-31 0001040971 us-gaap:FairValueInputsLevel3Member us-gaap:EstimateOfFairValueFairValueDisclosureMember 2018-12-31 0001040971 us-gaap:CarryingReportedAmountFairValueDisclosureMember 2019-12-31 0001040971 us-gaap:FairValueInputsLevel3Member us-gaap:CarryingReportedAmountFairValueDisclosureMember 2018-12-31 0001040971 slg:MortgageAndJrMortgageLoanWithAnInitialMaturityDateOfApril2017Member slg:FixedRateMember 2018-05-31 0001040971 slg:AccruedInterestPayableAndOtherMember us-gaap:FairValueInputsLevel1Member 2019-12-31 0001040971 slg:AccruedInterestPayableAndOtherMember us-gaap:FairValueInputsLevel3Member 2019-12-31 0001040971 us-gaap:FairValueInputsLevel3Member 2019-12-31 0001040971 slg:AccruedInterestPayableAndOtherMember us-gaap:FairValueInputsLevel2Member 2019-12-31 0001040971 us-gaap:FairValueInputsLevel2Member us-gaap:CommercialMortgageBackedSecuritiesMember 2019-12-31 0001040971 us-gaap:FairValueInputsLevel2Member 2019-12-31 0001040971 us-gaap:FairValueInputsLevel1Member 2019-12-31 0001040971 slg:AccruedInterestPayableAndOtherMember 2019-12-31 0001040971 us-gaap:FairValueInputsLevel1Member us-gaap:EquitySecuritiesMember 2019-12-31 0001040971 slg:AccruedInterestPayableAndOtherMember 2018-12-31 0001040971 us-gaap:FairValueInputsLevel1Member us-gaap:EquitySecuritiesMember 2018-12-31 0001040971 us-gaap:FairValueInputsLevel2Member 2018-12-31 0001040971 us-gaap:FairValueInputsLevel3Member 2018-12-31 0001040971 us-gaap:FairValueInputsLevel1Member 2018-12-31 0001040971 us-gaap:FairValueInputsLevel2Member us-gaap:CommercialMortgageBackedSecuritiesMember 2018-12-31 0001040971 slg:AccruedInterestPayableAndOtherMember us-gaap:FairValueInputsLevel2Member 2018-12-31 0001040971 slg:AccruedInterestPayableAndOtherMember us-gaap:FairValueInputsLevel3Member 2018-12-31 0001040971 slg:AccruedInterestPayableAndOtherMember us-gaap:FairValueInputsLevel1Member 2018-12-31 0001040971 us-gaap:InterestRateContractMember 2019-01-01 2019-12-31 0001040971 us-gaap:InterestRateContractMember 2017-01-01 2017-12-31 0001040971 us-gaap:InterestRateContractMember 2018-01-01 2018-12-31 0001040971 us-gaap:InterestExpenseMember 2019-01-01 2019-12-31 0001040971 slg:IncomeLossFromEquityMethodInvestmentsMember 2019-01-01 2019-12-31 0001040971 slg:InterestRateSwapExpiringJanuary20262Member 2019-12-31 0001040971 slg:InterestRateSwapExpiringinJuly2023Member 2019-12-31 0001040971 slg:InterestRateSwapExpiringMay2020Member 2019-12-31 0001040971 slg:InterestRateSwapExpiringJanuary2024Member 2019-12-31 0001040971 slg:InterestRateSwapExpiringDecember2020Member 2019-12-31 0001040971 slg:InterestRateSwapExpiringinJuly20232Member 2019-12-31 0001040971 slg:InterestRateSwapExpiringNovember2020Member 2019-12-31 0001040971 slg:InterestRateSwapExpiringJanuary2026Member 2019-12-31 0001040971 slg:InterestRateSwapExpiringNovember20202Member 2019-12-31 0001040971 slg:InterestRateSwapExpiringMarch2021Member 2019-12-31 0001040971 us-gaap:InterestRateContractMember 2019-12-31 0001040971 us-gaap:ConsolidatedPropertiesMember 2019-12-31 0001040971 us-gaap:UnconsolidatedPropertiesMember 2019-12-31 0001040971 us-gaap:UnconsolidatedPropertiesMember 2018-12-31 0001040971 us-gaap:ConsolidatedPropertiesMember 2018-12-31 0001040971 us-gaap:MultiemployerPlansPensionMember 2019-01-01 2019-12-31 0001040971 us-gaap:MultiemployerPlansPensionMember 2017-07-01 2018-06-30 0001040971 slg:HealthPlanMember 2019-01-01 2019-12-31 0001040971 slg:HealthPlanMember 2017-07-01 2019-06-30 0001040971 us-gaap:MultiemployerPlansPensionMember 2016-07-01 2017-06-30 0001040971 slg:HealthPlanMember 2016-07-01 2017-06-30 0001040971 us-gaap:MultiemployerPlansPensionMember 2017-07-01 2019-06-30 0001040971 slg:HealthPlanMember 2017-07-01 2018-06-30 0001040971 slg:HealthPlanMember 2017-01-01 2017-12-31 0001040971 slg:MultiemployerPlansOtherPlansMember 2018-01-01 2018-12-31 0001040971 us-gaap:MultiemployerPlansPensionMember 2018-01-01 2018-12-31 0001040971 slg:MultiemployerPlansOtherPlansMember 2019-01-01 2019-12-31 0001040971 slg:MultiemployerPlansOtherPlansMember 2017-01-01 2017-12-31 0001040971 us-gaap:MultiemployerPlansPensionMember 2017-01-01 2017-12-31 0001040971 slg:HealthPlanMember 2018-01-01 2018-12-31 0001040971 slg:BelmontInsuranceCompanyMember 2019-12-31 0001040971 slg:TiconderogaInsuranceCompanyMember 2019-12-31 0001040971 slg:ThirdAvenue711Member 2019-12-31 0001040971 slg:BelmontInsuranceCompanyMember 2018-12-31 0001040971 us-gaap:OperatingSegmentsMember slg:RealEstateSegmentMember 2019-01-01 2019-12-31 0001040971 us-gaap:OperatingSegmentsMember slg:StructuredFinanceSegmentMember 2019-01-01 2019-12-31 0001040971 us-gaap:OperatingSegmentsMember slg:RealEstateSegmentMember 2018-01-01 2018-12-31 0001040971 us-gaap:OperatingSegmentsMember slg:StructuredFinanceSegmentMember 2017-01-01 2017-12-31 0001040971 us-gaap:OperatingSegmentsMember slg:RealEstateSegmentMember 2018-12-31 0001040971 us-gaap:OperatingSegmentsMember slg:StructuredFinanceSegmentMember 2018-01-01 2018-12-31 0001040971 us-gaap:OperatingSegmentsMember slg:RealEstateSegmentMember 2017-01-01 2017-12-31 0001040971 us-gaap:OperatingSegmentsMember slg:RealEstateSegmentMember 2019-12-31 0001040971 us-gaap:OperatingSegmentsMember slg:StructuredFinanceSegmentMember 2019-12-31 0001040971 us-gaap:OperatingSegmentsMember slg:StructuredFinanceSegmentMember 2018-12-31 0001040971 2019-10-01 2019-12-31 0001040971 2019-07-01 2019-09-30 0001040971 2019-01-01 2019-03-31 0001040971 2019-04-01 2019-06-30 0001040971 2018-07-01 2018-09-30 0001040971 2018-04-01 2018-06-30 0001040971 2018-10-01 2018-12-31 0001040971 2018-01-01 2018-03-31 0001040971 srt:SubsidiariesMember 2019-10-01 2019-12-31 0001040971 srt:SubsidiariesMember 2019-01-01 2019-03-31 0001040971 srt:SubsidiariesMember 2019-07-01 2019-09-30 0001040971 srt:SubsidiariesMember 2019-04-01 2019-06-30 0001040971 srt:SubsidiariesMember 2018-10-01 2018-12-31 0001040971 srt:SubsidiariesMember 2018-07-01 2018-09-30 0001040971 srt:SubsidiariesMember 2018-01-01 2018-03-31 0001040971 srt:SubsidiariesMember 2018-04-01 2018-06-30 0001040971 slg:AllowanceForTenantAndOtherReceivablesMember 2017-12-31 0001040971 slg:AllowanceForDeferredRentReceivableMember 2019-01-01 2019-12-31 0001040971 slg:AllowanceForDeferredRentReceivableMember 2017-01-01 2017-12-31 0001040971 slg:AllowanceForDeferredRentReceivableMember 2018-01-01 2018-12-31 0001040971 slg:AllowanceForDeferredRentReceivableMember 2019-12-31 0001040971 slg:AllowanceForDeferredRentReceivableMember 2016-12-31 0001040971 slg:AllowanceForTenantAndOtherReceivablesMember 2019-01-01 2019-12-31 0001040971 slg:AllowanceForTenantAndOtherReceivablesMember 2018-01-01 2018-12-31 0001040971 slg:AllowanceForTenantAndOtherReceivablesMember 2018-12-31 0001040971 slg:AllowanceForTenantAndOtherReceivablesMember 2016-12-31 0001040971 slg:AllowanceForTenantAndOtherReceivablesMember 2017-01-01 2017-12-31 0001040971 slg:AllowanceForDeferredRentReceivableMember 2018-12-31 0001040971 slg:AllowanceForDeferredRentReceivableMember 2017-12-31 0001040971 slg:AllowanceForTenantAndOtherReceivablesMember 2019-12-31 0001040971 slg:Amsterdam1080Member 2019-12-31 0001040971 slg:SevenOneNineSeventhAvenueMember 2019-12-31 0001040971 slg:A30East40thStreetMember 2019-12-31 0001040971 slg:A410TenthAvenueMember 2019-12-31 0001040971 slg:East400Street58Member 2019-12-31 0001040971 slg:AvenueOfTheAmericas1185Member 2019-12-31 0001040971 slg:SixthAvenue635Member 2019-12-31 0001040971 slg:LandmarkSquare7Member 2019-12-31 0001040971 slg:FifthAvenue609Member 2019-12-31 0001040971 slg:LandmarkSquare1To6Member 2019-12-31 0001040971 slg:SixthAvenue641Member 2019-12-31 0001040971 slg:FifthAvenue461Member 2019-12-31 0001040971 slg:MadisonAvenue625Member 2019-12-31 0001040971 srt:OtherPropertyMember 2019-12-31 0001040971 slg:LexingtonAvenue485Member 2019-12-31 0001040971 slg:East42ndStreet110Member 2019-12-31 0001040971 slg:A315West33rdStreetMember 2019-12-31 0001040971 slg:ThirdAvenue750Member 2019-12-31 0001040971 slg:A110GreeneStreetMember 2019-12-31 0001040971 slg:ParkAvenue304Member 2019-12-31 0001040971 slg:MadisonAvenue762Member 2019-12-31 0001040971 slg:A752760MadisonAvenueMember 2019-12-31 0001040971 slg:A106SpringStreetMemberMember 2019-12-31 0001040971 slg:WashingtonBoulevard1055Member 2019-12-31 0001040971 slg:W57Street555Member 2019-12-31 0001040971 slg:ParkAvenue125Member 2019-12-31 0001040971 slg:ThirdAvenue711Member 2019-12-31 0001040971 slg:WilliamsburgMember 2019-12-31 0001040971 slg:LexingtonAvenue420Member 2019-12-31 0001040971 slg:A113GreeneStreetMember 2019-12-31 0001040971 slg:A1MadisonAveMember 2019-12-31 0001040971 slg:A712MadisonAvenueMember 2019-12-31 0001040971 slg:ChurchStreet100Member 2019-12-31 0001040971 slg:SeventhAvenue810Member 2019-12-31 0001040971 slg:AvenueOfTheAmericas1350Member 2019-12-31 0001040971 slg:A185BroadwayMember 2019-12-31 iso4217:USD xbrli:shares xbrli:pure xbrli:shares iso4217:USD slg:parcel slg:Tenant utreg:sqft slg:building slg:joint_venture slg:agreement utreg:acre slg:extension slg:segment slg:unit slg:note slg:loan slg:increase slg:unit xbrli:shares slg:fungible_unit
 
UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549
______________________________________________________________________
FORM 10-K
ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934
For the fiscal year ended December 31, 2019
OR
TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934
For the transition period from                to                
Commission File Number: 1-13199 (SL Green Realty Corp.)
Commission File Number: 33-167793-02 (SL Green Operating Partnership, L.P.)
______________________________________________________________________
SL GREEN REALTY CORP.
SL GREEN OPERATING PARTNERSHIP, L.P.
(Exact name of registrant as specified in its charter)
______________________________________________________________________
SL Green Realty Corp.
Maryland
13-3956775
SL Green Operating Partnership, L.P.
Delaware
13-3960938
 
(State or other jurisdiction of
incorporation or organization)
(I.R.S. Employer
Identification No.)
420 Lexington AvenueNew YorkNY 10170
(Address of principal executive offices—Zip Code)

(212594-2700
(Registrant's telephone number, including area code)
______________________________________________________________________
SECURITIES REGISTERED PURSUANT TO SECTION 12(B) OF THE ACT:
Registrant
 
Trading Symbol
 
Title of Each Class
 
Name of Each Exchange on Which Registered
SL Green Realty Corp.
 
SLG
 
Common Stock, $0.01 par value
 
New York Stock Exchange
SL Green Realty Corp.
 
SLG.PRI
 
6.500% Series I Cumulative Redeemable Preferred Stock, $0.01 par value
 
New York Stock Exchange

SECURITIES REGISTERED PURSUANT TO SECTION 12(G) OF THE ACT: None
Indicate by check mark if the registrant is a well-known seasoned issuer, as defined in Rule 405 of the Securities Act. 
SL Green Realty Corp.    Yes x    No o                SL Green Operating Partnership, L.P.    Yes o    No x
Indicate by check mark if the registrant is not required to file reports pursuant to Section 13 or Section 15(d) of the Act. 
SL Green Realty Corp.    Yes o    No x                SL Green Operating Partnership, L.P.    Yes o    No x
Indicate by check mark whether the registrant (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the registrant was required to file such reports), and (2) has been subject to such filing requirements for the past 90 days. 
SL Green Realty Corp.    Yes x    No o                SL Green Operating Partnership, L.P.    Yes x    No o
Indicate by check mark whether the registrant has submitted electronically every Interactive Data File required to be submitted pursuant to Rule 405 of Regulation S-T (§232.405 of this chapter) during the preceding 12 months (or for such shorter period that the registrant was required to submit such files). 
SL Green Realty Corp.     Yes x    No o                SL Green Operating Partnership, L.P.    Yes x    No o
Indicate by check mark if disclosure of delinquent filers pursuant to Item 405 of Regulation S-K is not contained herein, and will not be contained, to the best of the registrant's knowledge, in definitive proxy or information statements incorporated by reference in Part III of this Form 10-K or any amendment to this Form 10-K. 
SL Green Realty Corp.    o                    SL Green Operating Partnership, L.P.    o
Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, a smaller reporting company, or an emerging growth company. See the definitions of "large accelerated filer," "accelerated filer," "smaller reporting company," and "emerging growth company" in Rule 12b-2 of the Exchange Act.
SL Green Realty Corp.
Large Accelerated Filer
x
 
Accelerated Filer
o
Non-Accelerated Filer
o
 
 
Smaller Reporting Company
 
Emerging Growth Company
 
 
 
 
 
If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act.
o
SL Green Operating Partnership, L.P.
Large Accelerated Filer
o
 
Accelerated Filer
o
Non-Accelerated Filer
x
 
 
Smaller Reporting Company
 
Emerging Growth Company
 
 
 
 
 
If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act.
o
Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Act). 
SL Green Realty Corp.    Yes     No x                SL Green Operating Partnership, L.P.    Yes     No x
The aggregate market value of the common stock held by non-affiliates of SL Green Realty Corp. (76,111,663 shares) was $6.1 billion based on the quoted closing price on the New York Stock Exchange for such shares on June 30, 2019.
As of February 27, 2020, 77,935,496 shares of SL Green Realty Corp.'s common stock, par value $0.01 per share, were outstanding. As of February 27, 2020, 1,025,366 common units of limited partnership interest of SL Green Operating Partnership, L.P. were held by non-affiliates. There is no established trading market for such units.
DOCUMENTS INCORPORATED BY REFERENCE
Portions of the SL Green Realty Corp.'s Proxy Statement for its 2020 Annual Stockholders' Meeting to be filed within 120 days after the end of the Registrant's fiscal year are incorporated by reference into Part III of this Annual Report on Form 10-K.
 




EXPLANATORY NOTE

This report combines the annual reports on Form 10-K for the year ended December 31, 2019 of SL Green Realty Corp. and SL Green Operating Partnership, L.P. Unless stated otherwise or the context otherwise requires, references to "SL Green Realty Corp.," the "Company" or "SL Green" mean SL Green Realty Corp. and its consolidated subsidiaries; and references to "SL Green Operating Partnership, L.P.," the "Operating Partnership" or "SLGOP" mean SL Green Operating Partnership, L.P. and its consolidated subsidiaries. The terms "we," "our" and "us" mean the Company and all the entities owned or controlled by the Company, including the Operating Partnership.
The Company is a Maryland corporation which operates as a self-administered and self-managed real estate investment trust, or REIT, and is the sole managing general partner of the Operating Partnership. As a general partner of the Operating Partnership, the Company has full, exclusive and complete responsibility and discretion in the day-to-day management and control of the Operating Partnership.
As of December 31, 2019, the Company owns 94.97% of the outstanding general and limited partnership interest in the Operating Partnership. The Company also owns 9,200,000 Series I Preferred Units of the Operating Partnership. As of December 31, 2019, noncontrolling investors held, in aggregate, a 5.03% limited partnership interest in the Operating Partnership. We refer to these interests as the noncontrolling interests in the Operating Partnership.
The Company and the Operating Partnership are managed and operated as one entity. The financial results of the Operating Partnership are consolidated into the financial statements of the Company. The Company has no significant assets other than its investment in the Operating Partnership. Substantially all of our assets are held by, and our operations are conducted through, the Operating Partnership. Therefore, the assets and liabilities of the Company and the Operating Partnership are substantially the same.
Noncontrolling interests in the Operating Partnership, stockholders' equity of the Company and partners' capital of the Operating Partnership are the main areas of difference between the consolidated financial statements of the Company and those of the Operating Partnership. The common limited partnership interests in the Operating Partnership not owned by the Company are accounted as noncontrolling interests, within mezzanine equity, in the Company's and the Operating Partnership's consolidated financial statements.
We believe combining the annual reports on Form 10-K of the Company and the Operating Partnership into this single report results in the following benefits:
Combined reports enhance investors' understanding of the Company and the Operating Partnership by enabling investors to view the business as a whole in the same manner as management views and operates the business;
Combined reports eliminate duplicative disclosure and provides a more streamlined and readable presentation since a substantial portion of the Company's disclosure applies to both the Company and the Operating Partnership; and
Combined reports create time and cost efficiencies through the preparation of one combined report instead of two separate reports.
To help investors understand the significant differences between the Company and the Operating Partnership, this report presents the following separate sections for each of the Company and the Operating Partnership:
consolidated financial statements;
the following notes to the consolidated financial statements:
Note 11, Noncontrolling Interests on the Company’s Consolidated Financial Statements;
Note 12, Stockholders' Equity of the Company;
Note 13, Partners' Capital of the Operating Partnership;
Note 22, Quarterly Financial Data of the Company (unaudited); and
Note 23, Quarterly Financial Data of the Operating Partnership (unaudited).
This report also includes separate Part II, Item 5. Market for Registrants' Common Equity and Related Stockholder Matters and Issuer Purchases of Equity Securities, Item 6. Selected Financial Data and Item 9A. Controls and Procedures sections and separate Exhibit 31 and 32 certifications for each of the Company and the Operating Partnership, respectively, in order to establish that the Chief Executive Officer and the Chief Financial Officer of the Company, in both their capacity as the principal executive officer and principal financial officer of the Company and the principal executive officer and principal financial officer of the general partner of the Operating Partnership, have made the requisite certifications and that the Company and the Operating Partnership are compliant with Rule 13a-15 and Rule 15d-15 of the Securities Exchange Act of 1934, as amended, or the Exchange Act.




SL GREEN REALTY CORP. AND SL GREEN OPERATING PARTNERSHIP, L.P.
TABLE OF CONTENTS

PART I
 
PART II
 
 
 
 
PART III

PART IV
 
 




PART I

ITEM 1. BUSINESS

General
SL Green Realty Corp. is a self-managed real estate investment trust, or REIT, engaged in the acquisition, development, ownership, management and operation of commercial and residential real estate properties, principally office properties, located in the New York metropolitan area. We were formed in June, 1997 for the purpose of continuing the commercial real estate business of S.L. Green Properties, Inc., our predecessor entity. S.L. Green Properties, Inc., which was founded in 1980 by Stephen L. Green, who serves as a member and the chairman emeritus of the Company's board of directors, had been engaged in the business of owning, managing, leasing, and repositioning office properties in Manhattan, a borough of New York City.
As of December 31, 2019, we owned the following interests in properties in the New York metropolitan area, primarily in midtown Manhattan. Our investments located outside of Manhattan are referred to as the Suburban properties:
 
 
 
 
Consolidated
 
Unconsolidated
 
Total
Location
 
Property Type
 
Number of Properties
 
Approximate Square Feet
 
Number of Properties
 
Approximate Square Feet
 
Number of Properties
 
Approximate Square Feet
 
Weighted Average Occupancy(1)
Commercial:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Manhattan
 
Office
 
20

 
12,387,091

 
10

 
11,216,183

 
30

 
23,603,274

 
94.5
%
 
 
Retail
 
6

(2)
320,430

 
8

 
289,050

 
14

 
609,480

 
98.4
%
 
 
Development/Redevelopment
(3)
6

 
189,538

 
1

 

 
7

 
189,538

 
84.9
%
 
 
Fee Interest
 

 

 
1

 

 
1

 

 
%
 
 
 
 
32

 
12,897,059

 
20

 
11,505,233

 
52

 
24,402,292

 
94.6
%
Suburban
 
Office
 
8

 
1,044,800

 

 

 
8

 
1,044,800

 
85.7
%
 
 
Retail
 
1

 
52,000

 

 

 
1

 
52,000

 
100.0
%
 
 
 
 
9

 
1,096,800

 

 

 
9

 
1,096,800

 
86.4
%
Total commercial properties
 
41

 
13,993,859

 
20

 
11,505,233

 
61

 
25,499,092

 
94.2
%
Residential:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Manhattan
 
Residential
 
2

(2)
445,105

 
8

 
1,663,774

 
10

 
2,108,879

 
95.7
%
Total residential properties
 
2

 
445,105

 
8

 
1,663,774

 
10

 
2,108,879

 
95.7
%
Total portfolio
 
43

 
14,438,964

 
28

 
13,169,007

 
71

 
27,607,971

 
94.3
%
(1)
The weighted average occupancy for commercial properties represents the total occupied square feet divided by total square footage at acquisition. The weighted average occupancy for residential properties represents the total occupied units divided by total available units.
(2)
As of December 31, 2019, we owned a building at 315 West 33rd Street, also known as The Olivia, that was comprised of approximately 270,132 square feet of retail space and approximately 222,855 square feet of residential space. For the purpose of this report, we have included the building in the number of retail properties we own. However, we have included only the retail square footage in the retail approximate square footage, and have listed the balance of the square footage as residential square footage.
(3)
Properties in Development are included in Number of Properties and have no Approximate Square Feet.
As of December 31, 2019, we also managed two office buildings owned by third parties encompassing approximately 2.1 million square feet, and held debt and preferred equity investments with a book value of $1.7 billion, including $0.1 billion of debt and preferred equity investments and other financing receivables that are included in balance sheet line items other than the Debt and Preferred Equity Investments line item.
Our corporate offices are located in midtown Manhattan at 420 Lexington Avenue, New York, New York 10170. As of December 31, 2019, we employed 1,033 employees, 290 of whom were employed in our corporate offices. We can be contacted at (212) 594-2700. We maintain a website at www.slgreen.com. On our website, you can obtain, free of charge, a copy of our annual reports on Form 10-K, quarterly reports on Form 10-Q, current reports on Form 8-K and amendments to those reports filed or furnished pursuant to Section 13(a) or 15(d) of the Exchange Act as soon as reasonably practicable after we file such material electronically with, or furnish it to, the Securities and Exchange Commission, or the SEC. We have also made available on our website our audit committee charter, compensation committee charter, nominating and corporate governance committee charter, code of business conduct and ethics and corporate governance principles. We do not intend for information contained on our website to be part of this annual report on Form 10-K. The SEC maintains a website (http://www.sec.gov) that contains reports, proxy and information statements, and other information regarding issuers that file electronically with the SEC.

4



Unless the context requires otherwise, all references to the "Company," "SL Green," "we," "our" and "us" in this annual report means SL Green Realty Corp., a Maryland corporation, and one or more of its subsidiaries, including the Operating Partnership, or, as the context may require, SL Green only or the Operating Partnership only, and "S.L. Green Properties" means S.L. Green Properties, Inc., a New York corporation, as well as the affiliated partnerships and other entities through which Stephen L. Green historically conducted commercial real estate activities.
Corporate Structure
In connection with the Company's initial public offering, or IPO, in August 1997, the Operating Partnership received a contribution of interests in real estate properties as well as a 95% economic, non-voting interest in the management, leasing and construction companies affiliated with S.L. Green Properties. We refer to these management, leasing and construction entities, which are owned by S.L. Green Management Corp, as the "Service Corporation." The Company is organized so as to qualify, and has elected to qualify as a REIT, under the Internal Revenue Code of 1986, as amended, or the Code.
Substantially all of our assets are held by, and all of our operations are conducted through, the Operating Partnership. We are the sole managing general partner of the Operating Partnership, and as of December 31, 2019, we owned 94.97% of its economic interests. All of the management and leasing operations with respect to our wholly-owned properties are conducted through SL Green Management LLC, or Management LLC. The Operating Partnership owns 100% of Management LLC.
In order to maintain the Company's qualification as a REIT while realizing income from management, leasing and construction contracts with third parties and joint venture properties, all of these service operations are conducted through the Service Corporation, a consolidated variable interest entity. We, through our Operating Partnership, receive substantially all of the cash flow from the Service Corporation's operations. All of the voting common stock of the Service Corporation is held by an entity owned and controlled by Stephen L. Green, who serves as a member and as the chairman emeritus of the Company's board of directors.
Business and Growth Strategies
SL Green is Manhattan's largest owner of office real estate and an investment-grade, S&P 500 company that is focused primarily on owning, managing and maximizing the value of Manhattan commercial properties.
Our core business is the ownership of high quality commercial properties and our primary business objective is to maximize the total return to stockholders, through growth in net income attributable to common stockholders and funds from operations, or FFO, and through asset value appreciation. The commercial real estate expertise resulting from owning, operating, investing, developing, redeveloping and lending on real estate in Manhattan for over 39 years has enabled us to invest in a collection of premier office and retail properties, selected multifamily residential assets, and high quality debt and preferred equity investments. We also own high quality commercial properties in the New York metropolitan area.
We are led by a strong, experienced management team that provides a foundation of skills in all aspects of real estate, including acquisitions, dispositions, management, leasing, development, redevelopment, and financing. It is with this team that we have achieved a market leading position in our targeted submarkets.
We seek to enhance the value of our company by executing strategies that include the following:
Leasing and property management, which capitalizes on our extensive presence and knowledge of the marketplaces in which we operate;
Acquiring office, retail and residential properties and employing our local market skills to reposition these assets to create incremental cash flow and capital appreciation;
Identifying properties well suited for development/redevelopment and maximizing the value of those properties through development/redevelopment or reconfiguration to match current workplace, retail and housing trends;
Investing in debt and preferred equity positions that generate consistently strong risk-adjusted returns, increase the breadth of our market insight, foster key market relationships and source potential future investment opportunities;
Executing dispositions through sales or joint ventures that harvest embedded equity which has been generated through management's value enhancing activities; and
Maintaining a prudently levered, liquid balance sheet with consistent access to diversified sources of property level and corporate capital.

5



Leasing and Property Management
We seek to capitalize on our management's extensive knowledge of Manhattan and the New York metropolitan area and the needs of our tenants through proactive leasing and management programs, which include: (i) use of in-depth market experience resulting from managing and leasing tens of millions of square feet of office, retail and residential space since the Company was founded; (ii) careful tenant management, which results in long average lease terms and a manageable lease expiration schedule; (iii) utilization of an extensive network of third-party brokers to supplement our in-house leasing team; (iv) use of comprehensive building management analysis and planning; and (v) a commitment to tenant satisfaction by providing high quality tenant services at competitive rental rates.
Property Acquisitions
We acquire properties for long-term value appreciation and earnings growth. This strategy has resulted in capital gains that increase our investment capital base. In implementing this strategy, we continually evaluate potential acquisition opportunities. These opportunities may come from new properties as well as acquisitions in which we already hold a joint venture interest or, from time to time, from our debt and preferred equity investments.
Through intimate knowledge of our markets we have developed an ability to source transactions with superior risk-adjusted returns by capturing off-market opportunities. In rising markets, we primarily seek to acquire strategic vacancies that provide the opportunity to take advantage of our exceptional leasing and repositioning capabilities to increase cash flow and property value. In stable or falling markets, we primarily target assets featuring credit tenancies with fully escalated in-place rents to provide cash flow stability near-term and the opportunity for increases over time.
We believe that we have many advantages over our competitors in acquiring core and non-core properties, both directly and through our joint venture program that includes a predominance of high quality institutional investors. Those advantages include: (i) senior management's long-tenured experience leading a full-service, fully-integrated real estate company focused, primarily, on the Manhattan market; (ii) the ability to offer tax-efficient structures to sellers through the exchange of ownership interests, including units in our Operating Partnership; and (iii) the ability to underwrite and close transactions on an expedited basis even when the transaction involves a complicated structure.
Property Dispositions
We continually evaluate our portfolio to identify those properties that are most likely to meet our long-term earnings and cash flow growth objectives and contribute to increasing portfolio value. Properties that no longer meet our objectives are evaluated for sale, or in certain cases, joint venture to release equity created through management's value enhancement programs or to take advantage of attractive market valuations.
We seek to efficiently deploy the capital proceeds generated from these dispositions into property acquisitions and debt and preferred equity investments that we expect will provide enhanced future capital gains and earnings growth opportunities. Management may also elect to utilize the capital proceeds from these dispositions to repurchase shares of our common stock, repay existing indebtedness of the Company or its subsidiaries, or increase cash liquidity.
Property Repositioning
Our extensive knowledge of the markets in which we operate and our ability to efficiently plan and execute capital projects provide the expertise to enhance returns by repositioning properties that are underperforming. Many of the properties we own or seek to acquire feature unique architectural design elements or other amenities and characteristics that can be appealing to tenants when fully exploited. Our strategic investment in these properties, combined with our active management and pro-active leasing, provide the opportunity to creatively meet market needs and generate favorable returns.
Development / Redevelopment
Our constant interactions with tenants and other market participants keep us abreast of innovations in workplace layout, store design and smart living. We leverage this information to identify properties primed for development or redevelopment to meet these demands and unlock value. The expertise and relationships that we have built from managing complex construction projects in New York City and its surrounding areas allow us to cost efficiently add new and renovated assets of the highest quality and desirability to our operating portfolio.
Debt and Preferred Equity Investments
We invest in well-collateralized debt and preferred equity investments in the markets in which we operate, primarily New York City, that generate attractive yields. See Note 5, "Debt and Preferred Equity Investments," in the accompanying consolidated financial statements. Knowledge of our markets and our leasing and asset management expertise provide underwriting capabilities that enable a highly educated assessment of risk and return. The benefits of this investment program, which has a carefully managed aggregate size, include the following:

6



Our typical investments provide high current returns at conservative exposure levels and, in certain cases, the potential for future capital gains. Our expertise and operating capabilities provide both insight and operating skills that mitigate risk.
In certain instances, these investments serve as a potential source of real estate acquisitions for us when a borrower seeks an efficient off-market transaction. Ownership knows that we are fully familiar with the asset through our existing investment, and that we can close more efficiently and quickly than others. Property owners may also provide us the opportunity to consider off-market transactions involving other properties because we have previously provided debt or preferred equity financing to them.
These investments are concentrated in Manhattan, which helps us gain market insight, awareness of upcoming investment opportunities and foster key relationships that may provide access to future investment opportunities.
Capital Resources
Our objective is to maintain multiple sources of corporate and property level capital to obtain the most appropriate and lowest cost of capital. This objective is supported by:
Property operations that generally provide stable and growing cash flows through market cycles due to favorable supply/demand metrics in Manhattan, long average lease terms, high credit quality tenants and superior leasing, operating and asset management skills;
Concentration of our activities in a Manhattan market that is consistently attractive to property investors and lenders through market cycles relative to other markets;
Maintaining strong corporate liquidity and careful management of future debt maturities; and
Maintaining access to corporate capital markets through balanced financing and investment activities that result in strong balance sheet and cash flow metrics.
Manhattan Office Market Overview
Manhattan is by far the largest office market in the United States containing more rentable square feet than the next four largest central business district office markets combined. The properties in our portfolio are primarily concentrated in some of Manhattan's most prominent midtown locations.
According to Cushman and Wakefield Research Services as of December 31, 2019, Manhattan has a total office inventory of approximately 408.9 million square feet, including approximately 250.7 million square feet in midtown. We estimate that approximately 13.6 million square feet of new construction class-A buildings over 250,000 square feet will become available between 2020 and 2024 in Manhattan, approximately 43.7% of which is pre-leased. We estimate that this increase is partially offset by approximately 5.5 million square feet which will be converted from office use to an alternative use. This will add only approximately 0.4% per year to Manhattan's total inventory, net of conversions, over the next five years.
While the addition of new supply to the Manhattan office inventory is nominal relative to the size of the overall market, we view any additional supply as a positive to the Manhattan office market given the older vintage of the majority of Manhattan’s office inventory and the desire of certain tenants to occupy new, high quality, efficient office space, which often isn’t available in older vintage properties. In addition, Manhattan’s office inventory has only grown by approximately 8.6 million square feet over the last 25 years.
According to Cushman and Wakefield Research Services the total volume of leases signed in Manhattan for the years ended December 31, 2019 and 2018 was 34.7 million and 35.9 million, respectively. Manhattan's diverse tenant base is exemplified by the following tables, which show the percentage of leasing volume attributable to each industry:

7



 
 
Percent of Manhattan Leasing Volume (1)
Industry
 
2019
 
2018
Technology, Advertising, Media, and Information ("TAMI")
 
38.1
%
 
15.7
%
Financial Services
 
19.7
%
 
25.6
%
Real Estates
 
12.1
%
 
17.5
%
Legal Services
 
7.4
%
 
8.5
%
Professional Services
 
6.1
%
 
7.4
%
Retail/Wholesale
 
4.6
%
 
5.9
%
Public Sector
 
3.9
%
 
6.2
%
Other
 
8.1
%
 
13.2
%
(1)
Source: Cushman and Wakefield Research Services
General Terms of Leases in the Manhattan Markets
Leases entered into for space in Manhattan typically contain terms that may not be contained in leases in other U.S. office markets. The initial term of leases entered into for space in Manhattan is generally seven to fifteen years. Tenants leasing space in excess of 10,000 square feet for an initial term of 10 years or longer often will negotiate an option to extend the term of the lease for one or two renewal periods, typically for a term of five years each. The base rent during the initial term often will provide for agreed-upon periodic increases over the term of the lease. Base rent for renewal terms is most often based upon the then fair market rental value of the premises as of the commencement date of the applicable renewal term (generally determined by binding arbitration in the event the landlord and the tenant are unable to mutually agree upon the fair market value), though base rent for a renewal period may be set at 95% of the then fair market rent. Very infrequently, leases may contain termination options whereby a tenant can terminate the lease obligation before the lease expiration date upon payment of a penalty together with repayment of the unamortized portion of the landlord's transaction costs (e.g., brokerage commissions, free rent periods, tenant improvement allowances, etc.).
In addition to base rent, a tenant will generally also pay its pro rata share of increases in real estate taxes and operating expenses for the building over a base year, which is typically the year during which the term of the lease commences, based upon the tenant's proportionate occupancy of the building. In some smaller leases (generally less than 10,000 square feet), in lieu of paying additional rent based upon increases in building operating expenses, base rent will be increased each year during the lease term by a set percentage on a compounding basis (though the tenant will still pay its pro rata share of increases in real estate taxes over a base year).
Tenants typically receive a free rent period following commencement of the lease term, which in some cases may coincide with the tenant's construction period.
The landlord most often supplies electricity either on a sub-metered basis at the landlord's cost plus a fixed percentage or on a rent inclusion basis (i.e., a fixed fee is added to the base rent for electricity, which amount may increase based upon increases in electricity rates or increases in electrical usage by the tenant). Base building services, other than electricity, such as heat, air conditioning, freight elevator service during business hours and base building cleaning typically are provided at no additional cost, but are included in the building's operating expenses. The tenant will typically pay additional rent only for services which exceed base building services or for services which are provided other than during normal business hours.
In a typical lease for a new tenant renting in excess of 10,000 square feet, the landlord will deliver the premises with existing improvements demolished. In such instances, the landlord will typically provide a tenant improvement allowance, which is a fixed sum that the landlord makes available to the tenant to reimburse the tenant for all or a portion of the tenant's initial construction of its premises. Such sum typically is payable as work progresses, upon submission by the tenant of invoices for the cost of construction and lien waivers. However, in certain leases (most often for relatively small amounts of space), the landlord will construct the premises for the tenant at a cost to the landlord not to exceed an agreed upon amount with the tenant paying any amount in excess of the agreed upon amount. In addition, landlords may rent space to a tenant that is "pre-built" (i.e., space that was constructed by the landlord in advance of lease signing and is ready to for the tenant to move in with the tenant selecting paint and carpet colors).

8



Occupancy
The following table sets forth the weighted average occupancy rates at our office properties based on space leased for properties owned by us as of December 31, 2019:
 
 
Percent Occupied as of December 31,
Property
 
2019
 
2018
Same-Store office properties - Manhattan (1) 
 
96.2%
 
96.0%
Manhattan office properties
 
94.5%
 
94.5%
Suburban office properties
 
85.7%
 
91.3%
Unconsolidated joint venture office properties
 
93.9%
 
95.4%
Portfolio (2)
 
94.3%
 
94.2%
(1)
All office properties located in Manhattan owned by us at January 1, 2018 and still owned by us in the same manner at December 31, 2019. Percent Occupied includes leases signed but not yet commenced.
(2)
Excludes properties under development.
Rent Growth
We are constantly evaluating our schedule of future lease expirations to mitigate occupancy risk while maximizing rent growth. We proactively manage future lease expirations based on our view of estimated current and future market conditions and asking rents. The following table sets forth our future lease expirations, excluding triple net leases, and management's estimates of market asking rents. Taking rents are typically lower than asking rents and may vary from building to building. There can be no assurances that our estimates of market rents are accurate or that market rents currently prevailing will not erode or outperform in the future.
 
 
ANNUAL LEASE EXPIRATIONS - MANHATTAN OPERATING PROPERTIES
 
 
Consolidated Properties
 
Joint Venture Properties
Year of Lease Expiration
 
Number of Expiring Leases (2)

Rentable Square Footage of Expiring Leases

Percentage of Total
Sq. Ft.

 Annualized Cash Rent of Expiring Leases

 
 Annualized Cash Rent Per Square Foot of Expiring Leases
$/psf (3)

Current Weighted Average Asking Rent
$/psf (4)

 
Number of Expiring Leases (2)

Rentable Square Footage of Expiring Leases

Percentage of Total
Sq. Ft.

 Annualized Cash Rent of Expiring Leases

 
 Annualized Cash Rent Per Square Foot of Expiring Leases
$/psf (3)

Current Weighted Average Asking Rent $/psf (4)

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2019 (1)
 
14

422,686

3.42
%
$35,203,898
 

$83.29


$69.38

 
2

1,714

0.02
%

$54,600

 

$31.86


$32.47

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1st Quarter 2020
 
14

108,121

0.87
%
$7,418,586
 

$68.61


$65.41

 
4

132,676

1.23
%

$8,212,220

 

$61.90


$75.46

2nd Quarter 2020
 
15

44,882

0.36
%
2,965,824

 
66.08

76.41

 
5

56,941

0.53
%
4,337,388

 
76.17

83.37

3rd Quarter 2020
 
19

243,599

1.97
%
15,140,069

 
62.15

62.17

 
4

30,098

0.28
%
2,196,793

 
72.99

73.26

4th Quarter 2020
 
28

1,478,732

11.95
%
100,725,841

 
91.21(5)

80.68(5)

 
5

30,276

0.28
%
3,011,293

 
99.46

86.37

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Total 2020
 
76

1,875,334

15.15
%
$126,250,320
 

$76.69


$72.02

 
18

249,991

2.32
%

$17,757,694

 

$71.03


$78.32

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2021
 
108

1,259,079

10.18
%
$77,936,064
 
$61.90
$67.88
 
26

291,807

2.70
%

$22,156,933

 

$75.93


$79.20

2022
 
97

822,698

6.65
%
67,030,173

 
81.48

82.72

 
31

894,293

8.28
%
83,342,706

 
93.19

95.10

2023
 
76

883,272

7.14
%
57,648,722

 
65.27

65.99

 
16

438,826

4.06
%
38,216,366

 
87.09

80.68

2024
 
60

399,467

3.23
%
28,380,429

 
71.05

71.32

 
24

1,003,426

9.29
%
106,754,273

 
106.39

87.20

2025
 
45

591,666

4.78
%
53,408,872

 
90.27

82.35

 
12

426,938

3.95
%
34,135,739

 
79.95

84.97

2026
 
30

781,269

6.32
%
55,151,891

 
70.59

68.48

 
20

499,312

4.62
%
50,595,762

 
101.33

103.74

2027
 
35

602,943

4.87
%
46,184,007

 
76.60

71.71

 
17

375,697

3.48
%
33,260,546

 
88.53

94.16

2028
 
38

599,486

4.85
%
44,180,538

 
73.70

76.07

 
18

206,956

1.92
%
21,542,167

 
104.09

100.76

Thereafter
 
91

4,132,832

33.41
%
242,723,273

 
58.73

66.56

 
47

6,408,455

59.36
%
427,998,688

 
66.79

82.80

 
 
670

12,370,732

100.00
%
$834,098,187
 
68.05(5)

70.23(5)

 
231

10,797,415

100.00
%

$835,815,474

 

$77.41


$85.72

(1)
Includes month to month holdover tenants that expired prior to December 31, 2019.
(2)
Tenants may have multiple leases.
(3)
Represents in place annualized rent allocated by year of expiration.
(4)
Management's estimate of current average asking rents for currently occupied space as of December 31, 2019. Taking rents are typically lower than asking rents and may vary from property to property.
(5)
Excludes Credit Suisse at One Madison Avenue. In January 2020, Credit Suisse entered into a lease termination agreement with the Company and vacated its space at the property.
Industry Segments
The Company is a REIT that is engaged in the acquisition, development, ownership, management and operation of commercial and residential real estate properties, principally office properties, located in the New York metropolitan area and has two reportable segments: real estate and debt and preferred equity investments. Our industry segments are discussed in Note 21, "Segment Information," in the accompanying consolidated financial statements.

9



At December 31, 2019, our real estate portfolio was primarily located in one geographical market, the New York metropolitan area. The primary sources of revenue are generated from tenant rents and escalations and reimbursement revenue. Real estate property operating expenses consist primarily of cleaning, security, maintenance, utility costs, real estate taxes and, at certain properties, ground rent expense. As of December 31, 2019, one tenant in our office portfolio, Credit Suisse, contributed 8.2% of our share of annualized cash rent. In January 2020, Credit Suisse executed a lease termination agreement with the Company and vacated its space at the property, thereby reducing its share of annualized cash rent to approximately 3.3%. No other tenant contributed more than 5.0% of our share of annualized cash rent. No property contributed in excess of 10.0% of our consolidated total revenue for 2019.
At December 31, 2019, we held debt and preferred equity investments with a book value of $1.7 billion, including $0.1 billion of debt and preferred equity investments and other financing receivables that are included in balance sheet line items other than the Debt and Preferred Equity Investments line item. At December 31, 2019, the assets underlying our debt and preferred equity investments were located in the New York metropolitan area. The primary sources of revenue are generated from interest and fee income.
Employees
At December 31, 2019, we employed 1,033 employees, 290 of whom were employed in our corporate offices. There are currently six collective bargaining agreements which cover the workforce that services substantially all of our properties.
Highlights from 2019
Our significant achievements from 2019 included:
Corporate
Repurchased 4.6 million shares of our common stock under our share repurchase program at an average price of $83.62 per share and increased the size of our share repurchase program by $500 million to $3.0 billion. From program inception through December 31, 2019, we have repurchased a cumulative total of 22.7 million shares of our common stock under the program at an average price of $95.66 per share.
Leasing
Signed 163 Manhattan office leases covering approximately 2.5 million square feet. The mark-to-market on signed Manhattan office leases was 38.1% higher in 2019 than the previously fully escalated rents on the same spaces.
Reached 65% leased at One Vanderbilt Avenue after signing new leases with KPS Capital Partners LP; Sentinel Capital Partners; and Oak Hill Advisors and lease expansions with The Carlyle Group and McDermott Will & Emery.
Reached 96.2% leased at 410 Tenth Avenue after signing new leases with First Republic Bank and Amazon.
Signed a lease renewal with BMW of Manhattan for 227,000 square feet at 555 West 57th Street.
Signed a new retail lease with Ulta Beauty for 12,040 square feet at 2 Herald Square.
Acquisitions
Entered into a contract to acquire 707 Eleventh Avenue for a gross purchase price of $90.0 million. The 160,000-square-foot office property will be redeveloped into a modern, Class-A building. The acquisition was closed in January 2020.
Closed on the acquisition of a majority and controlling interest in 410 Tenth Avenue at a gross purchase price of $440 million.
Closed on the acquisition from our joint venture partner of the remaining 10% interest in 110 Greene Street that we did not already own at a gross asset valuation of $256.5 million.
Took possession of the retail co-op at 106 Spring Street in Soho. This property previously served as collateral for a debt and preferred equity investment and was acquired through a negotiated transaction with the sponsor of the investment.
Dispositions
Closed on the sale of 360 Hamilton Avenue in White Plains, New York and 100, 200 and 500 Summit Lake Drive in Valhalla, New York.
Closed on the sale of the development site at 562 Fifth Avenue for a sale price of $52.4 million.
Closed on the sale of the development site at 1640 Flatbush Avenue in Brooklyn for a sale price of $16.2 million.
Closed on the sale of 1010 Washington Boulevard in Stamford, Connecticut for a sale price of $23.1 million.

10



Entered into a contract to sell 220 East 42nd Street, also known as The News Building, for total consideration of $815.0 million.
Sold a 49% interest in the prime retail condominium at 115 Spring Street in Soho at a gross asset valuation of $66.6 million.
Together with our joint venture partner, closed on the sale of 521 Fifth Avenue for a sale price of $381.0 million.
Closed on the sale of our 20.0% interest in 131-137 Spring Street to the owner of the remaining 80.0% interest. The transaction generated net cash proceeds to the Company of $15.2 million.
Debt and Preferred Equity Investments
Originated and retained, or acquired, $0.7 billion in debt and preferred equity investments, inclusive of advances under future funding obligations, discount and fee amortization, and paid-in-kind interest, net of premium amortization, and recorded $1.2 billion of proceeds from sales, repayments and participations.
Finance
Together with our joint venture partner, closed on the refinancing of 55 West 46th Street, also known as Tower 46. The new $198.0 million mortgage replaces the previous $195.0