XML 56 R41.htm IDEA: XBRL DOCUMENT
v3.25.2

Significant Accounting Policies (Tables) | 6 Months Ended
--- | ---
Jun. 30, 2025
Accounting Policies [Abstract] |
Schedule of Identified Intangible Assets and Intangible Liabilities | The following summarizes our identified intangible assets (acquired above-market leases and in-place leases) and intangible liabilities (acquired below-market leases) as of June 30, 2025 and December 31, 2024 (in thousands):
| June 30, 2025 |  | December 31, 2024
Identified intangible assets (included in other assets): |  |  |
Gross amount | $ | 405,682 |  |  | $ | 378,277 |
Accumulated amortization | (215,029) |  |  | (197,211) |
Net | $ | 190,653 |  |  | $ | 181,066 |
Identified intangible liabilities (included in deferred revenue): |  |  |
Gross amount | $ | 249,564 |  |  | $ | 243,703 |
Accumulated amortization | (206,892) |  |  | (204,092) |
Net | $ | 42,672 |  |  | $ | 39,611 |
Schedule of Marketable Securities | As of June 30, 2025 and December 31, 2024, we held the following marketable securities (in thousands):
| June 30, 2025 |  | December 31, 2024
Commercial mortgage-backed securities - available-for-sale | $ | 17,151 |  |  | $ | 17,323 |
Commercial mortgage-backed securities - held-to-maturity | $ | — |  |  | $ | 5,489 |
Total investment in marketable securities | $ | 17,151 |  |  | $ | 22,812 |
Schedule of Real Estate CMBS Securitization Trusts | As of June 30, 2025 and December 31, 2024, we consolidated the following CMBS securitization trusts (in thousands):
| June 30, 2025 |  | December 31, 2024 |  | Maturity
Type | Fair Value |  | Principal Value |  |  | Fair Value (2) | Principal Value |  |
Real estate loans held by consolidated securitization vehicles (1) | $ | 1,431,362 |  |  | $ | 1,549,044 |  |  |  | $ | 709,095 |  | $ | 894,000 |  |  |  | 2023 - 2025 | (3)
Senior obligations of consolidated securitization vehicles | 1,431,362 |  |  | 1,549,044 |  |  |  | 590,131 |  | 688,346 |  |  |  | 2023 - 2025 | (3)
Real estate loans held by consolidated securitization vehicles in excess of senior obligations of consolidated securitization vehicles | $ | — |  |  | $ | — |  |  |  | $ | 118,964 |  | $ | 205,654 |  |  |  |  |
(1)Excludes real estate loans held by the Fund. (2)Includes $134.8 million and $34.2 million of assets and liabilities, respectively, for a loan that is accounted for on an amortized cost basis. (3)The Company is in discussions with the respective borrowers on the resolution of the past maturities.
Schedule of Properties Contributed of Annualized Cash Rent | For the three months ended June 30, 2025, the following properties contributed more than 5.0% of our annualized cash rent from office properties, including our share of annualized cash rent from joint venture office properties:
Property | Three months ended June 30, 2025
One Vanderbilt Avenue | 13.7%
11 Madison Avenue | 7.3%
420 Lexington Ave | 6.9%
245 Park Avenue | 6.4%
1515 Broadway | 6.3%
1185 Avenue of the Americas | 5.9%

X
- Definition Tabular disclosure of the aggregate amount of intangible assets and liabilities. + References No definition available. + Details
Name: | slg_ScheduleOfIntangibleAssetsAndLiabilitiesTableTextBlock
Namespace Prefix: | slg_
Data Type: | dtr-types:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- References No definition available. + Details
Name: | us-gaap_AccountingPoliciesAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Tabular disclosure of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale). + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 320 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 9 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org/1943274/2147481800/320-10-50-9 Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 320 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 3 -Publisher FASB -URI https://asc.fasb.org/1943274/2147481800/320-10-50-3 Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 320 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org/1943274/2147481800/320-10-50-2 Reference 4: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 320 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (c) -Publisher FASB -URI https://asc.fasb.org/1943274/2147481800/320-10-50-2 Reference 5: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 320 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org/1943274/2147481800/320-10-50-2 Reference 6: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 320 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (aa) -Publisher FASB -URI https://asc.fasb.org/1943274/2147481800/320-10-50-2 Reference 7: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 320 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (aaa) -Publisher FASB -URI https://asc.fasb.org/1943274/2147481800/320-10-50-2 Reference 8: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 320 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (d) -Publisher FASB -URI https://asc.fasb.org/1943274/2147481800/320-10-50-2 Reference 9: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 320 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 3 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org/1943274/2147481800/320-10-50-3 Reference 10: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 320 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 3 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org/1943274/2147481800/320-10-50-3 Reference 11: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 320 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 3 -Subparagraph (c) -Publisher FASB -URI https://asc.fasb.org/1943274/2147481800/320-10-50-3 Reference 12: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 320 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 3 -Subparagraph (d) -Publisher FASB -URI https://asc.fasb.org/1943274/2147481800/320-10-50-3 + Details
Name: | us-gaap_DebtSecuritiesAvailableForSaleTableTextBlock
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition Tabular disclosure of all information related to the key inputs and assumptions used in measuring the fair value of assets obtained or liabilities incurred, as the result of a sale of financial assets, relating to the transferor's continuing involvement, if any, at the time of securitization, asset-backed financing arrangement, or similar transfer (including at a minimum, but not limited to, and if applicable, quantitative information about discount rates, expected prepayments including the expected weighted-average life of prepayable financial assets, and anticipated credit losses, including expected static pool losses). + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Topic 860 -SubTopic 20 -Section 50 -Paragraph 3 -Subparagraph (c) -Publisher FASB -URI https://asc.fasb.org/1943274/2147481326/860-20-50-3 + Details
Name: | us-gaap_ScheduleOfAssumptionsForFairValueOnSecuritizationDateOfInterestsContinuedToBeHeldByTransferorServicingAssetsOrServicingLiabilitiesTextBlock
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition Tabular disclosure of the nature of a concentration, a benchmark to which it is compared, and the percentage that the risk is to the benchmark. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 275 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 18 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482861/275-10-50-18 Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 275 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 20 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482861/275-10-50-20 + Details
Name: | us-gaap_SchedulesOfConcentrationOfRiskByRiskFactorTextBlock
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:textBlockItemType
Balance Type: | na
Period Type: | duration