Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019
Operating Activities
Net income	$ 193,741	$ 226,510
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	169,381	143,258
Equity in net loss from unconsolidated joint ventures	15,013	12,780
Distributions of cumulative earnings from unconsolidated joint ventures	206	566
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	(65,590)
(Gain) loss on sale of real estate, net	(137,520)	1,049
Loan loss reserves and other investment reserves, net of recoveries	18,061	0
Deferred rents receivable	2,577	(5,674)
Non-cash lease expense	6,547	6,798
Other non-cash adjustments	7,648	3,754
Changes in operating assets and liabilities:
Tenant and other receivables	(57,325)	(1,109)
Related party receivables	4,395	4,481
Deferred lease costs	(11,143)	(32,183)
Other assets	(17,363)	(295)
Accounts payable, accrued expenses, other liabilities and security deposits	39,318	5,299
Deferred revenue	(3,503)	(427)
Change in lease liability - operating leases	(5,728)	(5,121)
Net cash provided by operating activities	224,305	217,915
Investing Activities
Acquisitions of real estate property	(86,846)	(262,343)
Additions to land, buildings and improvements	(183,297)	(93,013)
Acquisition deposits and deferred purchase price	0	(228)
Investments in unconsolidated joint ventures	(18,318)	(97,447)
Distributions in excess of cumulative earnings from unconsolidated joint ventures	76,091	45,241
Net proceeds from disposition of real estate/joint venture interest	249,820	138,526
Other investments	(7,324)	(1,056)
Origination of debt and preferred equity investments	(265,574)	(523,476)
Repayments or redemption of debt and preferred equity investments	639,267	327,392
Net cash (used in) provided by investing activities	403,819	(466,404)
Financing Activities
Proceeds from mortgages and other loans payable	642,196	427,352
Repayments of mortgages and other loans payable	(266,795)	(43,630)
Proceeds from revolving credit facility and senior unsecured notes	1,275,000	940,000
Repayments of revolving credit facility and senior unsecured notes	(815,000)	(770,000)
Proceeds from stock options exercised and DRSPP issuance	364	263
Repurchase of common stock	(352,048)	(109,313)
Redemption of preferred stock	(59,800)	(15,142)
Redemption of OP units	(18,066)	(15,851)
Distributions to noncontrolling interests in other partnerships	(596)	(271)
Contributions from noncontrolling interests in other partnerships	8,186	2,469
Acquisition of subsidiary interest from noncontrolling interest	(1,536)	(25,791)
Distributions to noncontrolling interests in the Operating Partnership	(5,110)	(7,353)
Dividends paid on common and preferred stock	(153,474)	(154,460)
Tax withholdings related to restricted share awards	(4,752)	(3,126)
Deferred loan costs	(16,510)	(14,624)
Principal payments of on financing lease liabilities	(330)	0
Net cash provided by financing activities	231,729	210,523
Net increase (decrease) in cash, cash equivalents, and restricted cash	859,853	(37,966)
Cash, cash equivalents, and restricted cash at beginning of year	241,430	279,113
Cash, cash equivalents, and restricted cash at end of period	1,101,283	241,147
Supplemental Disclosure of Non-Cash Investing and Financing Activities:
Conversion of units in the Operating Partnership	8,744	446
Exchange of preferred equity investment for real estate or equity in joint venture	119,467	0
Tenant improvements and capital expenditures payable	6,653	9,021
Fair value adjustment to noncontrolling interest in the Operating Partnership	31,144	43,835
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	49,687	0
Transfer of liabilities related to assets held for sale	38,272	0
Removal of fully depreciated commercial real estate properties	534	5,728
Contribution to consolidated joint venture by noncontrolling interest	0	48,223
Share repurchase payable	8,820	0
Recognition of right of use assets and related lease liabilities	114,974	389,120
Total cash, cash equivalents, and restricted cash	1,101,283	241,147
SL Green Operating Partnership
Operating Activities
Net income	193,741	226,510
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	169,381	143,258
Equity in net loss from unconsolidated joint ventures	15,013	12,780
Distributions of cumulative earnings from unconsolidated joint ventures	206	566
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	(65,590)
(Gain) loss on sale of real estate, net	(137,520)	1,049
Loan loss reserves and other investment reserves, net of recoveries	18,061	0
Deferred rents receivable	2,577	(5,674)
Non-cash lease expense	6,547	6,798
Other non-cash adjustments	7,648	3,754
Changes in operating assets and liabilities:
Tenant and other receivables	(57,325)	(1,109)
Related party receivables	4,395	4,481
Deferred lease costs	(11,143)	(32,183)
Other assets	(17,363)	(295)
Accounts payable, accrued expenses, other liabilities and security deposits	39,318	5,299
Deferred revenue	(3,503)	(427)
Change in lease liability - operating leases	(5,728)	(5,121)
Net cash provided by operating activities	224,305	217,915
Investing Activities
Acquisitions of real estate property	(86,846)	(262,343)
Additions to land, buildings and improvements	(183,297)	(93,013)
Acquisition deposits and deferred purchase price	0	(228)
Investments in unconsolidated joint ventures	(18,318)	(97,447)
Distributions in excess of cumulative earnings from unconsolidated joint ventures	76,091	45,241
Net proceeds from disposition of real estate/joint venture interest	249,820	138,526
Other investments	(7,324)	(1,056)
Origination of debt and preferred equity investments	(265,574)	(523,476)
Repayments or redemption of debt and preferred equity investments	639,267	327,392
Net cash (used in) provided by investing activities	403,819	(466,404)
Financing Activities
Proceeds from mortgages and other loans payable	642,196	427,352
Repayments of mortgages and other loans payable	(266,795)	(43,630)
Proceeds from revolving credit facility and senior unsecured notes	1,275,000	940,000
Repayments of revolving credit facility and senior unsecured notes	(815,000)	(770,000)
Proceeds from stock options exercised and DRSPP issuance	364	263
Repurchase of common stock	(352,048)	(109,313)
Redemption of preferred stock	(59,800)	(15,142)
Redemption of OP units	(18,066)	(15,851)
Distributions to noncontrolling interests in other partnerships	(596)	(271)
Contributions from noncontrolling interests in other partnerships	8,186	2,469
Acquisition of subsidiary interest from noncontrolling interest	(1,536)	(25,791)
Dividends paid on common and preferred stock	(158,584)	(161,813)
Tax withholdings related to restricted share awards	(4,752)	(3,126)
Deferred loan costs	(16,510)	(14,624)
Principal payments of on financing lease liabilities	(330)	0
Net cash provided by financing activities	231,729	210,523
Net increase (decrease) in cash, cash equivalents, and restricted cash	859,853	(37,966)
Cash, cash equivalents, and restricted cash at beginning of year	241,430	279,113
Cash, cash equivalents, and restricted cash at end of period	1,101,283	241,147
Supplemental Disclosure of Non-Cash Investing and Financing Activities:
Conversion of units in the Operating Partnership	8,744	446
Tenant improvements and capital expenditures payable	6,653	9,021
Fair value adjustment to noncontrolling interest in the Operating Partnership	31,144	43,835
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	49,687	0
Transfer of liabilities related to assets held for sale	38,272	0
Removal of fully depreciated commercial real estate properties	534	5,728
Contribution to consolidated joint venture by noncontrolling interest	0	48,223
Share repurchase payable	8,820	0
Recognition of right of use assets and related lease liabilities	114,974	389,120
Total cash, cash equivalents, and restricted cash	$ 1,101,283	$ 241,147