Consolidated Statements of Cash Flows (Partnership) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023
Operating Activities
Net income (loss)	$ 11,084	$ (439,279)
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Depreciation and amortization	158,892	205,086
Equity in net (income) loss from unconsolidated joint ventures	(100,057)	44,470
Distributions of cumulative earnings from unconsolidated joint ventures	306	514
Equity in net (gain) loss on sale of interest in unconsolidated joint venture interest/real estate	(19,006)	79
Purchase price and other fair value adjustments	36,321	6,987
Depreciable real estate reserves and impairment	65,839	305,527
(Gain) loss on sale of real estate, net	(4,730)	27,813
Loan loss reserves and other investment reserves, net of recoveries	0	6,890
Gain on early extinguishment of debt	(17,777)	0
Deferred rents receivable	(2,166)	(16,195)
Non-cash lease expense	15,147	15,477
Other non-cash adjustments	31,460	6,645
Changes in operating assets and liabilities:
Tenant and other receivables	(12,693)	(2,852)
Related party receivables	181	16,466
Deferred lease costs	(11,920)	(8,066)
Other assets	(11,332)	(14,169)
Accounts payable, accrued expenses, other liabilities and security deposits	(57,291)	23,655
Deferred revenue	1,616	9,978
Lease liability - operating leases	(12,454)	(7,688)
Net Cash Provided by (Used in) Operating Activities	71,420	181,338
Investing Activities
Additions to land, buildings and improvements	(162,691)	(194,035)
Acquisition deposits and deferred purchase price	(12,817)	0
Investments in unconsolidated joint ventures	(371,948)	(119,522)
Distributions in excess of cumulative earnings from unconsolidated joint ventures	99,307	108,884
Net proceeds from disposition of real estate/joint venture interest	478,151	547,605
Investments in marketable securities	(5,604)	0
Investments in real estate loans held by consolidated securitization vehicles	(108,893)
Other investments	(7,350)	(17,545)
Origination of debt and preferred equity investments	(9,126)	(53,703)
Repayments or redemption of debt and preferred equity investments	63,496	0
Net Cash Provided by (Used in) Investing Activities	(37,475)	271,684
Financing Activities
Proceeds from mortgages and other loans payable	900	0
Repayments of mortgages and other loans payable	(36,488)	(4,340)
Proceeds from revolving credit facility, term loans and unsecured notes	920,000	358,000
Repayments of revolving credit facility, term loans and unsecured notes	(745,000)	(808,000)
Proceeds from stock options exercised and DRSPP issuance	14,291	439
Redemption of preferred units	0	(11,700)
Redemption of OP units	(31,491)	(8,900)
Distributions to noncontrolling interests in other partnerships	(4,567)	(1,614)
Contributions from noncontrolling interests in other partnerships	1,823	3,580
Distributions paid on common and preferred units	(162,787)	(172,920)
Other obligations related to secured borrowing	0	129,656
Deferred loan costs	(475)	(729)
Net cash used in financing activities	(54,339)	(527,753)
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Including Exchange Rate Effect	(20,394)	(74,731)
Cash, cash equivalents, and restricted cash at beginning of year	335,519	384,054
Cash, cash equivalents, and restricted cash at end of period	315,125	309,323
Supplemental Disclosure of Non-Cash Investing and Financing Activities:
Exchange of debt investment for real estate or equity in joint venture	0	349,946
Fair value adjustment to noncontrolling interest in the Operating Partnership	77,400	8,072
Investment in joint venture	10,639	0
Consolidation of a subsidiary	6,678	0
Consolidation of mortgage loan payable	205,000	0
Acquisition of subsidiary interest from noncontrolling interest	5,674	0
Contribution to consolidated joint venture interest	0	8,134
Extinguishment of debt	18,000	0
Debt and preferred equity investments	1,133	0
Removal of fully depreciated commercial real estate properties	4,774	7,747
Share repurchase or redemption payable	9,514	0
Consolidation of securitization vehicle assets	600,521	0
Consolidation of securitization vehicle liabilities	600,521	0
Restricted cash	126,909	119,573
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents	315,125	309,323
Cash and cash equivalents	188,216	189,750
SL Green Operating Partnership
Operating Activities
Net income (loss)	11,084	(439,279)
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Depreciation and amortization	158,892	205,086
Equity in net (income) loss from unconsolidated joint ventures	(100,057)	44,470
Distributions of cumulative earnings from unconsolidated joint ventures	306	514
Equity in net (gain) loss on sale of interest in unconsolidated joint venture interest/real estate	(19,006)	79
Purchase price and other fair value adjustments	36,321	6,987
Depreciable real estate reserves and impairment	65,839	305,527
(Gain) loss on sale of real estate, net	(4,730)	27,813
Loan loss reserves and other investment reserves, net of recoveries	0	6,890
Gain on early extinguishment of debt	(17,777)	0
Deferred rents receivable	(2,166)	(16,195)
Non-cash lease expense	15,147	15,477
Other non-cash adjustments	31,460	6,645
Changes in operating assets and liabilities:
Tenant and other receivables	(12,693)	(2,852)
Related party receivables	181	16,466
Deferred lease costs	(11,920)	(8,066)
Other assets	(11,332)	(14,169)
Accounts payable, accrued expenses, other liabilities and security deposits	(57,291)	23,655
Deferred revenue	1,616	9,978
Lease liability - operating leases	(12,454)	(7,688)
Net Cash Provided by (Used in) Operating Activities	71,420	181,338
Investing Activities
Additions to land, buildings and improvements	(162,691)	(194,035)
Acquisition deposits and deferred purchase price	(12,817)	0
Investments in unconsolidated joint ventures	(371,948)	(119,522)
Distributions in excess of cumulative earnings from unconsolidated joint ventures	99,307	108,884
Net proceeds from disposition of real estate/joint venture interest	478,151	547,605
Investments in marketable securities	(5,604)	0
Investments in real estate loans held by consolidated securitization vehicles	(108,893)	0
Other investments	(7,350)	(17,545)
Origination of debt and preferred equity investments	(9,126)	(53,703)
Repayments or redemption of debt and preferred equity investments	63,496	0
Net Cash Provided by (Used in) Investing Activities	(37,475)	271,684
Financing Activities
Proceeds from mortgages and other loans payable	900	0
Repayments of mortgages and other loans payable	(36,488)	(4,340)
Proceeds from revolving credit facility, term loans and unsecured notes	920,000	358,000
Repayments of revolving credit facility, term loans and unsecured notes	(745,000)	(808,000)
Proceeds from stock options exercised and DRSPP issuance	14,291	439
Redemption of preferred units	0	(11,700)
Redemption of OP units	(31,491)	(8,900)
Distributions to noncontrolling interests in other partnerships	(4,567)	(1,614)
Contributions from noncontrolling interests in other partnerships	1,823	3,580
Distributions paid on common and preferred units	(173,332)	(184,145)
Other obligations related to secured borrowing	0	129,656
Deferred loan costs	(475)	(729)
Net cash used in financing activities	(54,339)	(527,753)
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Including Exchange Rate Effect	(20,394)	(74,731)
Cash, cash equivalents, and restricted cash at end of period	315,125	309,323
Supplemental Disclosure of Non-Cash Investing and Financing Activities:
Exchange of debt investment for real estate or equity in joint venture	0	349,946
Fair value adjustment to noncontrolling interest in the Operating Partnership	77,400	8,072
Investment in joint venture	10,639	0
Deconsolidation of a subsidiary	0	101,351
Consolidation of a subsidiary	6,678	0
Consolidation of mortgage loan payable	205,000	0
Acquisition of subsidiary interest from noncontrolling interest	5,674	0
Contribution to consolidated joint venture interest	0	8,134
Extinguishment of debt	18,000	0
Debt and preferred equity investments	1,133	0
Removal of fully depreciated commercial real estate properties	4,774	7,747
Share repurchase or redemption payable	9,514	0
Consolidation of securitization vehicle assets	600,521	0
Consolidation of securitization vehicle liabilities	600,521	0
Restricted cash	126,909	119,573
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents	315,125	309,323
Cash and cash equivalents	$ 188,216	$ 189,750