XML 117 R94.htm IDEA: XBRL DOCUMENT
v3.25.0.1

Debt and Preferred Equity Investments - Schedule of Preferred Equity Investments with an Aggregate Weighted Average Current Yield (Details) - USD ($) $ in Thousands | 12 Months Ended |  |  |
--- | --- | --- | --- | ---
Dec. 31, 2024 | Dec. 31, 2023 | Dec. 31, 2022 | Dec. 31, 2021
Preferred equity investment |  |  |  |
Mortgage loans on real estate, interest rate | 6.02% |  |  |
Carrying Value | $ 303,726 | $ 346,745 |  |
Allowance for loan loss | (13,520) | (13,520) | $ (6,630) | $ (6,630)
Total after allowance for loan loss | $ 23,700 | 8,800 |  |
Preferred Equity Investments |  |  |  |
Preferred equity investment |  |  |  |
Mortgage loans on real estate, interest rate | 6.55% |  |  |
Future funding obligations | $ 0 |  |  |
Senior financing | 250,000 |  |  |
Total after allowance for loan loss | 136,720 | 128,000 |  |
Preferred Equity, February 2027 |  |  |  |
Preferred equity investment |  |  |  |
Future funding obligations | 0 |  |  |
Senior financing | 250,000 |  |  |
Carrying Value | $ 136,720 | $ 128,000 |  |
Preferred Equity |  |  |  |
Preferred equity investment |  |  |  |
Aggregate weighted average current yield | 6.55% |  |  |
Carrying Value | $ 136,720 |  |  |

X
- Definition Loans and Leases Receivable, Funding Obligation + References No definition available. + Details
Name: | slg_LoansandLeasesReceivableFundingObligation
Namespace Prefix: | slg_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount as of the balance sheet date of debt which holds a position senior to the entity's investment in a mortgage loan on real estate. + References No definition available. + Details
Name: | slg_MortgageLoansOnRealEstateSeniorDebtOnInvestment
Namespace Prefix: | slg_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Interest rate of mortgage loan within investment in mortgage loan on real estate by entity with substantial portion of business acquiring and holding investment real estate or interest in real estate. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name Regulation S-X (SX) -Number 210 -Section 12 -Subsection 29 -Paragraph Column B -Publisher SEC Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 948 -SubTopic 310 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.12-29(Column B)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479628/948-310-S99-1 + Details
Name: | srt_MortgageLoansOnRealEstateInterestRate
Namespace Prefix: | srt_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | duration

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 Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name Regulation S-X (SX) -Number 210 -Section 12 -Subsection 29 -Publisher SEC Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 948 -SubTopic 310 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.12-29) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479628/948-310-S99-1 + Details
Name: | srt_MortgageLoansOnRealEstateLineItems
Namespace Prefix: | srt_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Weighted average interest rate of debt outstanding. + References No definition available. + Details
Name: | us-gaap_DebtWeightedAverageInterestRate
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Amount excluding accrued interest, of allowance for credit loss on financing receivable. Excludes net investment in lease. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 45 -Paragraph 1 -Publisher FASB -URI https://asc.fasb.org/1943274/2147479344/326-20-45-1 + Details
Name: | us-gaap_FinancingReceivableAllowanceForCreditLossExcludingAccruedInterest
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amortized cost excluding accrued interest, after allowance for credit loss, of financing receivable. Excludes net investment in lease. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 45 -Paragraph 1 -Publisher FASB -URI https://asc.fasb.org/1943274/2147479344/326-20-45-1 + Details
Name: | us-gaap_FinancingReceivableExcludingAccruedInterestAfterAllowanceForCreditLoss
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition The balance represents the amount of loans that are secured by real estate mortgages, offset by the reserve to cover probable credit losses on the loan portfolio. + References Reference 1: http://www.xbrl.org/2003/role/exampleRef -Topic 944 -SubTopic 80 -Name Accounting Standards Codification -Section 55 -Paragraph 14 -Publisher FASB -URI https://asc.fasb.org/1943274/2147480078/944-80-55-14 Reference 2: http://www.xbrl.org/2003/role/exampleRef -Topic 944 -SubTopic 80 -Name Accounting Standards Codification -Section 55 -Paragraph 9 -Publisher FASB -URI https://asc.fasb.org/1943274/2147480078/944-80-55-9 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Topic 944 -SubTopic 210 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-03(a)(1)(c)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147478777/944-210-S99-1 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Topic 944 -SubTopic 210 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-03(a)(1)(6)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147478777/944-210-S99-1 + Details
Name: | us-gaap_MortgageLoansOnRealEstateCommercialAndConsumerNet
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Details
Name: | srt_MortgageLoansOnRealEstateLoanTypeAxis=slg_PreferredEquityInvestmentsInMortgageLoansMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_MortgageLoansOnRealEstateLoanTypeAxis=slg_PreferredEquityFebruary2027Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_MortgageLoansOnRealEstateLoanTypeAxis=slg_PreferredEquityMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |