XML 89 R74.htm IDEA: XBRL DOCUMENT
v3.21.2

Mortgages and Other Loans Payable (Details) | 1 Months Ended | 9 Months Ended |  |  |  |
--- | --- | --- | --- | --- | --- | ---
Oct. 31, 2021 | Jun. 30, 2021 | Sep. 30, 2021 USD ($) extension | Jul. 31, 2021 | Dec. 31, 2020 USD ($) | Jun. 30, 2018 USD ($) | Apr. 30, 2018 USD ($)
Debt Instrument [Line Items] |  |  |  |  |  |  |
Total fixed rate debt |  |  | $ 1,076,153,000 |  | $ 1,083,683,000 |  |
Total floating rate debt |  |  | 352,581,000 |  | 917,677,000 |  |
Total mortgages and other loans payable |  |  | 1,428,734,000 |  | 2,001,360,000 |  |
Deferred financing costs, net of amortization |  |  | (6,447,000) |  | (21,388,000) |  |
Total mortgages and other loans payable, net |  |  | 1,422,287,000 |  | 1,979,972,000 |  |
Outstanding under line of credit facility |  |  | 216,902,000 |  | 105,262,000 |  |
Book value of collateral |  |  | 2,100,000,000 |  | 2,500,000,000 |  |
220 East 42nd Street |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |
Ownership interest disposed |  |  |  | 49.00% |  |  |
FHLB Facility, January 2021, 1 |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |
Total floating rate debt |  |  | 0 |  | 10,000,000 |  |
FHLB Facility, January 2021, 2 |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |
Total floating rate debt |  |  | 0 |  | 15,000,000 |  |
FHLB Facility January 2021 |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |
Total floating rate debt |  |  | 0 |  | 35,000,000 |  |
2017 Master Repurchase Agreement |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |
Total floating rate debt |  |  | 0 |  | 0 |  |
Maximum facility capacity |  |  | 400,000,000 |  |  | $ 300,000,000 | $ 400,000,000
Extension option exercised, term |  | 1 year |  |  |  |  |
Outstanding under line of credit facility |  |  | 0 |  |  |  |
100 Church Street |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |
Total fixed rate debt |  |  | $ 201,405,000 |  | 204,875,000 |  |
100 Church Street | Weighted Average |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |
Interest rate, fixed rate debt (as a percent) |  |  | 4.68% |  |  |  |
420 Lexington Avenue |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |
Total fixed rate debt |  |  | $ 290,032,000 |  | 294,035,000 |  |
420 Lexington Avenue | Weighted Average |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |
Interest rate, fixed rate debt (as a percent) |  |  | 3.99% |  |  |  |
Landmark Square |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |
Total fixed rate debt |  |  | $ 100,000,000 |  | 100,000,000 |  |
Landmark Square | Weighted Average |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |
Interest rate, fixed rate debt (as a percent) |  |  | 4.90% |  |  |  |
485 Lexington Avenue |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |
Total fixed rate debt |  |  | $ 450,000,000 |  | 450,000,000 |  |
485 Lexington Avenue | Weighted Average |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |
Interest rate, fixed rate debt (as a percent) |  |  | 4.25% |  |  |  |
1080 Amsterdam Avenue |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |
Total fixed rate debt |  |  | $ 34,716,000 |  | 34,773,000 |  |
Total fixed rate debt |  |  | 33,900,000 |  |  |  |
Subordinate loan |  |  | $ 900,000 |  |  |  |
1080 Amsterdam Avenue | Weighted Average |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |
Interest rate, fixed rate debt (as a percent) |  |  | 3.59% |  |  |  |
1080 Amsterdam Avenue | Mortgage loan | Weighted Average |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |
Interest rate, fixed rate debt (as a percent) |  |  | 3.50% |  |  |  |
Interest rate period |  |  | 5 years |  |  |  |
1080 Amsterdam Avenue | Subordinate loan | Weighted Average |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |
Interest rate, fixed rate debt (as a percent) |  |  | 7.00% |  |  |  |
185 Broadway |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |
Total floating rate debt |  |  | $ 189,699,000 |  | 158,478,000 |  |
185 Broadway | Weighted Average |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |
Interest rate, floating rate debt (as a percent) |  |  | 2.85% |  |  |  |
609 Fifth Avenue |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |
Total floating rate debt |  |  | $ 52,882,000 |  | 57,651,000 |  |
609 Fifth Avenue | Weighted Average |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |
Interest rate, floating rate debt (as a percent) |  |  | 2.95% |  |  |  |
719 Seventh Avenue |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |
Total floating rate debt |  |  | $ 50,000,000 |  | 50,000,000 |  |
719 Seventh Avenue | Weighted Average |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |
Interest rate, floating rate debt (as a percent) |  |  | 1.20% |  |  |  |
690 Madison Avenue |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |
Total floating rate debt |  |  | $ 60,000,000 |  | 0 |  |
690 Madison Avenue | Weighted Average |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |
Interest rate, floating rate debt (as a percent) |  |  | 1.00% |  |  |  |
220 East 42nd Street |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |
Total floating rate debt |  |  | $ 0 |  | 510,000,000 |  |
220 East 42nd Street | Weighted Average |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |
Interest rate, floating rate debt (as a percent) |  |  |  |  |  |  |
133 Greene Street |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |
Total floating rate debt |  |  | $ 0 |  | 15,523,000 |  |
106 Spring Street |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |
Total floating rate debt |  |  | 0 |  | 38,025,000 |  |
712 Madison Avenue |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |
Total floating rate debt |  |  | 0 |  | $ 28,000,000 |  |
Construction Loans | 185 Broadway |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |
Maximum facility capacity |  |  | $ 225,000,000 |  |  |  |
Term (in Years) |  |  | 3 years |  |  |  |
Number of extension options | extension |  |  | 2 |  |  |  |
Period of extension options |  |  | 1 year |  |  |  |
Construction Loans | 185 Broadway | Subsequent Event |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |
Period of extension options | 1 year |  |  |  |  |  |

X
- Definition Debt Instrument, Extension Option Exercised, Term + References No definition available. + Details
Name: | slg_DebtInstrumentExtensionOptionExercisedTerm
Namespace Prefix: | slg_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Debt Instrument, Number of Extension Options + References No definition available. + Details
Name: | slg_DebtInstrumentNumberofExtensionOptions
Namespace Prefix: | slg_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition Debt Instrument, Period of Extension Option + References No definition available. + Details
Name: | slg_DebtInstrumentPeriodofExtensionOption
Namespace Prefix: | slg_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Disposal Group, Including Discontinued Operation, Ownership Interest Disposed + References No definition available. + Details
Name: | slg_DisposalGroupIncludingDiscontinuedOperationOwnershipInterestDisposed
Namespace Prefix: | slg_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Long-Term Debt, Percentage Bearing Fixed Interest, Period + References No definition available. + Details
Name: | slg_LongTermDebtPercentageBearingFixedInterestPeriod
Namespace Prefix: | slg_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition The portion of the carrying amount of long-term secured loans outstanding as of the balance sheet date, including current maturities, which accrues interest at a set, unchanging rate. + References No definition available. + Details
Name: | slg_SecuredDebtBearingFixedInterestAmount
Namespace Prefix: | slg_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Secured Debt, Bearing Fixed Interest, Mortgage Amount + References No definition available. + Details
Name: | slg_SecuredDebtBearingFixedInterestMortgageAmount
Namespace Prefix: | slg_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Secured Debt, Bearing Fixed Interest, Subordinate Loan Amount + References No definition available. + Details
Name: | slg_SecuredDebtBearingFixedInterestSubordinateLoanAmount
Namespace Prefix: | slg_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition The portion of the carrying amount of long-term secured loans outstanding as of the balance sheet date, including current maturities, which accrues interest at a rate subject to change from time to time. + References No definition available. + Details
Name: | slg_SecuredDebtBearingVariableInterestAmount
Namespace Prefix: | slg_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Secured Debt, Deferred Finance Costs, Net + References No definition available. + Details
Name: | slg_SecuredDebtDeferredFinanceCostsNet
Namespace Prefix: | slg_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Secured Debt, Gross + References No definition available. + Details
Name: | slg_SecuredDebtGross
Namespace Prefix: | slg_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition The aggregate fair value of assets that are already posted, at the end of the reporting period, as collateral for derivative instruments with credit-risk-related contingent features. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4H -Subparagraph (d) -URI http://asc.fasb.org/extlink&oid=121590274&loc=SL5624258-113959 + Details
Name: | us-gaap_CollateralAlreadyPostedAggregateFairValue
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
Name: | us-gaap_DebtInstrumentLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Period of time between issuance and maturity of debt instrument, in PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. + References No definition available. + Details
Name: | us-gaap_DebtInstrumentTerm
Namespace Prefix: | us-gaap_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition The carrying value as of the balance sheet date of the current and noncurrent portions of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(22)) -URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03(16)) -URI http://asc.fasb.org/extlink&oid=120398452&loc=d3e534808-122878 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-03(16)) -URI http://asc.fasb.org/extlink&oid=120400017&loc=d3e572229-122910 + Details
Name: | us-gaap_LineOfCredit
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.19(b),22(b)) -URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682 + Details
Name: | us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition The interest rate applicable to the portion of the carrying amount of long-term borrowings outstanding as of the balance sheet date, including current maturities, which accrues interest at a set, unchanging rate. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.22(a)(1)) -URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682 + Details
Name: | us-gaap_LongTermDebtPercentageBearingFixedInterestRate
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition The interest rate applicable to the portion of the carrying amount of long-term borrowings outstanding as of the balance sheet date, including current maturities, which accrues interest at a rate subject to change from time to time. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.22(a)(1)) -URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682 + Details
Name: | us-gaap_LongTermDebtPercentageBearingVariableInterestRate
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Carrying value as of the balance sheet date, including the current and noncurrent portions, of collateralized debt obligations (with maturities initially due after one year or beyond the operating cycle, if longer). Such obligations include mortgage loans, chattel loans, and any other borrowings secured by assets of the borrower. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-03(a)(16)) -URI http://asc.fasb.org/extlink&oid=120400017&loc=d3e572229-122910 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03(16)) -URI http://asc.fasb.org/extlink&oid=120398452&loc=d3e534808-122878 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(22)) -URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682 + Details
Name: | us-gaap_SecuredDebt
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Details
Name: | us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis=slg_East220Street42Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=slg_FHLBFacilityJanuary20211Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=slg_FHLBFacilityJanuary20212Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=slg_FHLBFacilityJanuary2021Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=slg_UncommittedMasterRepurchaseAgreement2017Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_StatementGeographicalAxis=slg_ChurchStreet100Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_RangeAxis=srt_WeightedAverageMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_StatementGeographicalAxis=slg_LexingtonAvenue420Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_StatementGeographicalAxis=slg_LandmarkSquareMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_StatementGeographicalAxis=slg_LexingtonAvenue485Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_StatementGeographicalAxis=slg_AmsterdamAvenue1080Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=us-gaap_MortgagesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=us-gaap_SeniorSubordinatedLoansMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_StatementGeographicalAxis=slg_A185BroadwayMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_StatementGeographicalAxis=slg_FifthAvenue609Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_StatementGeographicalAxis=slg_SevenOneNineSeventhAvenueMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_StatementGeographicalAxis=slg_A690MadisonAvenueMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_StatementGeographicalAxis=slg_East220Street42Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_StatementGeographicalAxis=slg_A133GreeneStreetMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_StatementGeographicalAxis=slg_A106SpringStreetMemberMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_StatementGeographicalAxis=slg_A712MadisonAvenueMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_CreditFacilityAxis=us-gaap_ConstructionLoansMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_SubsequentEventTypeAxis=us-gaap_SubsequentEventMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |