Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
Operating Activities
Net income	$ 214,418	$ 267,232
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	265,048	216,834
Equity in net loss from unconsolidated joint ventures	15,445	22,644
Distributions of cumulative earnings from unconsolidated joint ventures	576	648
Equity in net gain on sale of interest in unconsolidated joint venture interest/real estate	0	(76,181)
Purchase price and other fair value adjustments	0	(69,389)
Depreciable real estate reserves and impairment	6,627	7,047
Gain on sale of real estate, net	(163,624)	(2,492)
Loan loss reserves and other investment reserves, net of recoveries	27,018	0
Deferred rents receivable	(3,459)	(10,005)
Non-cash lease expense	9,735	10,255
Other non-cash adjustments	14,874	(11,766)
Changes in operating assets and liabilities:
Tenant and other receivables	(43,069)	(7,564)
Related party receivables	4,195	8,921
Deferred lease costs	(12,472)	(38,542)
Other assets	(55,301)	(47,139)
Accounts payable, accrued expenses, other liabilities and security deposits	43,256	18,737
Deferred revenue	13,206	18,255
Change in lease liability - operating leases	(8,530)	(8,062)
Net cash provided by operating activities	327,943	299,433
Investing Activities
Acquisitions of real estate property	(86,846)	(261,596)
Additions to land, buildings and improvements	(281,651)	(150,742)
Acquisition deposits and deferred purchase price	0	(228)
Investments in unconsolidated joint ventures	(39,724)	(114,050)
Distributions in excess of cumulative earnings from unconsolidated joint ventures	104,300	62,576
Net proceeds from disposition of real estate/joint venture interest	333,037	138,948
Other investments	(3,921)	(2,491)
Origination of debt and preferred equity investments	(353,797)	(555,951)
Repayments or redemption of debt and preferred equity investments	703,625	642,634
Net cash provided by (used in) investing activities	375,023	(240,900)
Financing Activities
Proceeds from mortgages and other loans payable	1,128,775	699,072
Repayments of mortgages and other loans payable	(710,352)	(162,024)
Proceeds from revolving credit facility and senior unsecured notes	1,275,000	1,090,000
Repayments of revolving credit facility and senior unsecured notes	(1,575,000)	(1,255,000)
Proceeds from stock options exercised and DRSPP issuance	566	302
Repurchase of common stock	(381,992)	(175,005)
Redemption of preferred stock	(82,750)	(15,142)
Redemption of OP units	(18,913)	(15,918)
Distributions to noncontrolling interests in other partnerships	(13,126)	(478)
Contributions from noncontrolling interests in other partnerships	12,404	4,873
Acquisition of subsidiary interest from noncontrolling interest	(1,536)	(25,791)
Distributions to noncontrolling interests in the Operating Partnership	(8,857)	(10,993)
Dividends paid on common and preferred stock	(224,147)	(230,804)
Tax withholdings related to restricted share awards	(4,752)	(3,126)
Deferred loan costs	(34,687)	(21,068)
Principal payments of on financing lease liabilities	(580)	0
Net cash used in financing activities	(639,947)	(121,102)
Net increase (decrease) in cash, cash equivalents, and restricted cash	63,019	(62,569)
Cash, cash equivalents, and restricted cash at beginning of year	241,430	279,113
Cash, cash equivalents, and restricted cash at end of period	304,449	216,544
Supplemental Disclosure of Non-Cash Investing and Financing Activities:
Conversion of units in the Operating Partnership	8,744	471
Exchange of preferred equity investment for real estate or equity in joint venture	119,497	0
Issuance of preferred units relating to a real estate acquisition	0	1,000
Tenant improvements and capital expenditures payable	11,993	10,040
Fair value adjustment to noncontrolling interest in the Operating Partnership	35,253	15,509
Deconsolidation of a subsidiary	0	395
Reversal of assets held for sale	391,664	0
Seller financed purchases	100,000	0
Debt and preferred equity reserves	4,638	0
Transfer of assets related to assets held for sale	0	403,488
Removal of fully depreciated commercial real estate properties	7,906	6,602
Contribution to consolidated joint venture by noncontrolling interest	0	48,223
Share repurchase payable	10,003	8,839
Recognition of right of use assets and related lease liabilities	57,500	389,120
Total cash, cash equivalents, and restricted cash	304,449	216,544
SL Green Operating Partnership
Operating Activities
Net income	214,418	267,232
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	265,048	216,834
Equity in net loss from unconsolidated joint ventures	15,445	22,644
Distributions of cumulative earnings from unconsolidated joint ventures	576	648
Equity in net gain on sale of interest in unconsolidated joint venture interest/real estate	0	(76,181)
Purchase price and other fair value adjustments	0	(69,389)
Depreciable real estate reserves and impairment	6,627	7,047
Gain on sale of real estate, net	(163,624)	(2,492)
Loan loss reserves and other investment reserves, net of recoveries	27,018	0
Deferred rents receivable	(3,459)	(10,005)
Non-cash lease expense	9,735	10,255
Other non-cash adjustments	14,874	(11,766)
Changes in operating assets and liabilities:
Tenant and other receivables	(43,069)	(7,564)
Related party receivables	4,195	8,921
Deferred lease costs	(12,472)	(38,542)
Other assets	(55,301)	(47,139)
Accounts payable, accrued expenses, other liabilities and security deposits	43,256	18,737
Deferred revenue	13,206	18,255
Change in lease liability - operating leases	(8,530)	(8,062)
Net cash provided by operating activities	327,943	299,433
Investing Activities
Acquisitions of real estate property	(86,846)	(261,596)
Additions to land, buildings and improvements	(281,651)	(150,742)
Acquisition deposits and deferred purchase price	0	(228)
Investments in unconsolidated joint ventures	(39,724)	(114,050)
Distributions in excess of cumulative earnings from unconsolidated joint ventures	104,300	62,576
Net proceeds from disposition of real estate/joint venture interest	333,037	138,948
Other investments	(3,921)	(2,491)
Origination of debt and preferred equity investments	(353,797)	(555,951)
Repayments or redemption of debt and preferred equity investments	703,625	642,634
Net cash provided by (used in) investing activities	375,023	(240,900)
Financing Activities
Proceeds from mortgages and other loans payable	1,128,775	699,072
Repayments of mortgages and other loans payable	(710,352)	(162,024)
Proceeds from revolving credit facility and senior unsecured notes	1,275,000	1,090,000
Repayments of revolving credit facility and senior unsecured notes	(1,575,000)	(1,255,000)
Proceeds from stock options exercised and DRSPP issuance	566	302
Repurchase of common stock	(381,992)	(175,005)
Redemption of preferred stock	(82,750)	(15,142)
Redemption of OP units	(18,913)	(15,918)
Distributions to noncontrolling interests in other partnerships	(13,126)	(478)
Contributions from noncontrolling interests in other partnerships	12,404	4,873
Acquisition of subsidiary interest from noncontrolling interest	(1,536)	(25,791)
Dividends paid on common and preferred stock	(233,004)	(241,797)
Tax withholdings related to restricted share awards	(4,752)	(3,126)
Deferred loan costs	(34,687)	(21,068)
Principal payments of on financing lease liabilities	(580)	0
Net cash used in financing activities	(639,947)	(121,102)
Net increase (decrease) in cash, cash equivalents, and restricted cash	63,019	(62,569)
Cash, cash equivalents, and restricted cash at beginning of year	241,430	279,113
Cash, cash equivalents, and restricted cash at end of period	304,449	216,544
Supplemental Disclosure of Non-Cash Investing and Financing Activities:
Conversion of units in the Operating Partnership	8,744	471
Exchange of preferred equity investment for real estate or equity in joint venture	119,497	0
Issuance of preferred units relating to a real estate acquisition	0	1,000
Tenant improvements and capital expenditures payable	11,993	10,040
Fair value adjustment to noncontrolling interest in the Operating Partnership	35,253	15,509
Deconsolidation of a subsidiary	0	395
Reversal of assets held for sale	391,664	0
Seller financed purchases	100,000	0
Debt and preferred equity reserves	4,638	0
Transfer of assets related to assets held for sale	0	403,488
Transfer of liabilities related to assets held for sale	0	0
Removal of fully depreciated commercial real estate properties	7,906	6,602
Contribution to consolidated joint venture by noncontrolling interest	0	48,223
Share repurchase payable	10,003	8,839
Recognition of right of use assets and related lease liabilities	57,500	389,120
Total cash, cash equivalents, and restricted cash	$ 304,449	$ 216,544