Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Operating Activities
Net income	$ 113,823	$ 924
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	72,925	98,895
Equity in net income from unconsolidated joint ventures	(4,036)	(6,614)
Distributions of cumulative earnings from unconsolidated joint ventures	7,510	5,468
Equity in net loss (gain) on sale of interest in unconsolidated joint venture interest/real estate	6,440	(2,047)
Purchase price and other fair value adjustments	(49,293)	0
Depreciable real estate reserves	0	56,272
Gain on sale of real estate, net	(23,521)	(567)
Gain on sale of investments in marketable securities	0	(3,262)
Deferred rents receivable	(3,120)	(11,722)
Other non-cash adjustments	12,155	23,245
Changes in operating assets and liabilities:
Tenant and other receivables	(1,847)	1,272
Related party receivables	(4,567)	(3,211)
Deferred lease costs	(7,679)	(9,421)
Other assets	(47,826)	(45,356)
Accounts payable, accrued expenses, other liabilities and security deposits	18,890	(16,327)
Deferred revenue and land leases payable	4,692	25,600
Net cash provided by operating activities	94,546	113,149
Investing Activities
Acquisitions of real estate property	(1,276)	0
Additions to land, buildings and improvements	(51,631)	(101,090)
Acquisition deposits and deferred purchase price	(3,020)	0
Investments in unconsolidated joint ventures	(51,158)	(8,000)
Distributions in excess of cumulative earnings from unconsolidated joint ventures	142,694	37,811
Net proceeds from disposition of real estate/joint venture interest	409,867	3,000
Proceeds from sale or redemption of marketable securities	0	54,363
Other investments	(21,687)	21,721
Origination of debt and preferred equity investments	(229,428)	(402,453)
Repayments or redemption of debt and preferred equity investments	261,641	411,969
Net cash provided by investing activities	456,002	17,321
Financing Activities
Proceeds from mortgages and other loans payable	99,115	778,445
Repayments of mortgages and other loans payable	(9,406)	(680,572)
Proceeds from revolving credit facility and senior unsecured notes	455,000	277,800
Repayments of revolving credit facility and senior unsecured notes	(495,000)	(277,800)
Proceeds from stock options exercised and DRIP issuance	771	8,808
Repurchase of common stock	(382,679)	(102)
Redemption of preferred stock	(150)	0
Distributions to noncontrolling interests in other partnerships	(276)	(469)
Contributions from noncontrolling interests in other partnerships	157	31,947
Distributions to noncontrolling interests in the Operating Partnership	(3,841)	(3,537)
Dividends / Distributions paid on common and preferred stock / units	(81,729)	(84,179)
Tax withholdings related to restricted share awards	(3,842)	(3,816)
Deferred loan costs and capitalized lease obligation	(429)	(7,712)
Net cash (used in) provided by financing activities	(422,309)	38,813
Net increase in cash, cash equivalents, and restricted cash	128,239	169,283
Cash, cash equivalents, and restricted cash at end of period	378,265	539,250
Supplemental Disclosure of Non-Cash Investing and Financing Activities:
Issuance of units in the Operating Partnership	15,448	18,240
Redemption of units in the Operating Partnership for stock	0	13,112
Derivative instruments at fair value	6,937	4,734
Tenant improvements and capital expenditures payable	15,952	7,087
Fair value adjustment to noncontrolling interest in Operating Partnership	3,645	15,548
Deconsolidation of subsidiaries	298,403	0
Transfer of assets related to assets held for sale	0	54,694
Transfer of liabilities related to assets held for sale	0	43
Deferred leasing payable	1,203	1,455
Removal of fully depreciated commercial real estate properties	106,142	2,043
Share repurchase payable	27,935	0
Total cash, cash equivalents, and restricted cash	378,265	539,250
SL Green Operating Partnership
Operating Activities
Net income	113,823	924
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	72,925	98,895
Equity in net income from unconsolidated joint ventures	(4,036)	(6,614)
Distributions of cumulative earnings from unconsolidated joint ventures	7,510	5,468
Equity in net loss (gain) on sale of interest in unconsolidated joint venture interest/real estate	6,440	(2,047)
Purchase price and other fair value adjustments	(49,293)	0
Depreciable real estate reserves	0	56,272
Gain on sale of real estate, net	(23,521)	(567)
Gain on sale of investments in marketable securities	0	(3,262)
Deferred rents receivable	(3,120)	(11,722)
Other non-cash adjustments	12,155	23,245
Changes in operating assets and liabilities:
Tenant and other receivables	(1,847)	1,272
Related party receivables	(4,567)	(3,211)
Deferred lease costs	(7,679)	(9,421)
Other assets	(47,826)	(45,356)
Accounts payable, accrued expenses, other liabilities and security deposits	18,890	(16,327)
Deferred revenue and land leases payable	4,692	25,600
Net cash provided by operating activities	94,546	113,149
Investing Activities
Acquisitions of real estate property	(1,276)	0
Additions to land, buildings and improvements	(51,631)	(101,090)
Acquisition deposits and deferred purchase price	(3,020)	0
Investments in unconsolidated joint ventures	(51,158)	(8,000)
Distributions in excess of cumulative earnings from unconsolidated joint ventures	142,694	37,811
Net proceeds from disposition of real estate/joint venture interest	409,867	3,000
Proceeds from sale or redemption of marketable securities	0	54,363
Other investments	(21,687)	21,721
Origination of debt and preferred equity investments	(229,428)	(402,453)
Repayments or redemption of debt and preferred equity investments	261,641	411,969
Net cash provided by investing activities	456,002	17,321
Financing Activities
Proceeds from mortgages and other loans payable	99,115	778,445
Repayments of mortgages and other loans payable	(9,406)	(680,572)
Proceeds from revolving credit facility and senior unsecured notes	455,000	277,800
Repayments of revolving credit facility and senior unsecured notes	(495,000)	(277,800)
Proceeds from stock options exercised and DRIP issuance	771	8,808
Repurchase of common stock	(382,679)	(102)
Redemption of preferred stock	(150)	0
Distributions to noncontrolling interests in other partnerships	(276)	(469)
Contributions from noncontrolling interests in other partnerships	157	31,947
Dividends / Distributions paid on common and preferred stock / units	(85,570)	(87,716)
Tax withholdings related to restricted share awards	(3,842)	(3,816)
Deferred loan costs and capitalized lease obligation	(429)	(7,712)
Net cash (used in) provided by financing activities	(422,309)	38,813
Net increase in cash, cash equivalents, and restricted cash	128,239	169,283
Cash, cash equivalents, and restricted cash at beginning of year	250,026	369,967
Cash, cash equivalents, and restricted cash at end of period	378,265	539,250
Supplemental Disclosure of Non-Cash Investing and Financing Activities:
Issuance of units in the Operating Partnership	15,448	18,240
Redemption of units in the Operating Partnership for stock	0	13,112
Derivative instruments at fair value	6,937	4,734
Tenant improvements and capital expenditures payable	15,952	7,087
Fair value adjustment to noncontrolling interest in Operating Partnership	3,645	15,548
Deconsolidation of subsidiaries	298,403	0
Transfer of assets related to assets held for sale	0	54,694
Transfer of liabilities related to assets held for sale	0	43
Deferred leasing payable	1,203	1,455
Removal of fully depreciated commercial real estate properties	106,142	2,043
Share repurchase payable	27,935	0
Total cash, cash equivalents, and restricted cash	$ 250,026	$ 369,967