Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017
Operating Activities
Net income	$ 229,722	$ 16,939
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	144,385	235,381
Equity in net income from unconsolidated joint ventures	(8,738)	(10,026)
Distributions of cumulative earnings from unconsolidated joint ventures	9,889	12,388
Equity in net gain on sale of interest in unconsolidated joint venture interest/real estate	(65,585)	(15,136)
Purchase price and other fair value adjustments	(60,442)	0
Depreciable real estate reserves	0	85,336
(Gain) loss on sale of real estate, net	(8,731)	3,256
Gain on sale of investments in marketable securities	0	(3,262)
Deferred rents receivable	(4,369)	(23,237)
Other non-cash adjustments	9,404	20,352
Changes in operating assets and liabilities:
Tenant and other receivables	(397)	1,447
Related party receivables	(1,116)	(7,869)
Deferred lease costs	(17,469)	(23,560)
Other assets	(4,329)	680
Accounts payable, accrued expenses, other liabilities and security deposits	22,867	(11,310)
Deferred revenue and land leases payable	1,121	29,471
Net cash provided by operating activities	246,212	310,850
Investing Activities
Acquisitions of real estate property	(9,733)	(19)
Additions to land, buildings and improvements	(96,577)	(165,262)
Acquisition deposits and deferred purchase price	(1,520)	0
Investments in unconsolidated joint ventures	(254,305)	(93,182)
Distributions in excess of cumulative earnings from unconsolidated joint ventures	178,892	93,688
Net proceeds from disposition of real estate/joint venture interest	760,335	61,248
Proceeds from sale or redemption of marketable securities	0	54,363
Other investments	(22,790)	3,014
Origination of debt and preferred equity investments	(603,575)	(854,577)
Repayments or redemption of debt and preferred equity investments	317,337	663,140
Net cash provided by (used in) investing activities	268,064	(237,587)
Financing Activities
Proceeds from mortgages and other loans payable	210,575	779,642
Repayments of mortgages and other loans payable	(22,864)	(693,243)
Proceeds from revolving credit facility and senior unsecured notes	1,475,000	1,072,800
Repayments of revolving credit facility and senior unsecured notes	(1,155,000)	(875,697)
Proceeds from stock options exercised and DRIP issuance	5,701	11,706
Repurchase of common stock	(724,696)	(211,599)
Redemption of preferred stock	(350)	(125)
Distributions to noncontrolling interests in other partnerships	(724)	(609)
Contributions from noncontrolling interests in other partnerships	1,828	33,009
Distributions to noncontrolling interests in the Operating Partnership	(7,712)	(7,112)
Dividends / Distributions paid on common and preferred stock / units	(160,699)	(168,678)
Other obligations related to loan participations	(3)	10,000
Tax withholdings related to restricted share awards	(3,842)	(3,879)
Deferred loan costs and capitalized lease obligation	(1,536)	(8,521)
Net cash used in financing activities	(384,322)	(62,306)
Net increase in cash, cash equivalents, and restricted cash	129,954	10,957
Cash, cash equivalents, and restricted cash at end of period	379,980	380,924
Supplemental Disclosure of Non-Cash Investing and Financing Activities:
Conversion of units in the Operating Partnership for common stock	1,560	13,242
Tenant improvements and capital expenditures payable	16,534	7,210
Fair value adjustment to noncontrolling interest in Operating Partnership	4,493	12,712
Deconsolidation of subsidiaries	298,403	328,644
Transfer of assets related to assets held for sale	593,995	173,918
Transfer of liabilities related to assets held for sale	265,538	149
Removal of fully depreciated commercial real estate properties	110,594	5,754
Share repurchase payable	31,605	41,598
Bond repurchase payable	0	65,416
Total cash, cash equivalents, and restricted cash	379,980	380,924
SL Green Operating Partnership
Operating Activities
Net income	229,722	16,939
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	144,385	235,381
Equity in net income from unconsolidated joint ventures	(8,738)	(10,026)
Distributions of cumulative earnings from unconsolidated joint ventures	9,889	12,388
Equity in net gain on sale of interest in unconsolidated joint venture interest/real estate	(65,585)	(15,136)
Purchase price and other fair value adjustments	(60,442)	0
Depreciable real estate reserves	0	85,336
(Gain) loss on sale of real estate, net	(8,731)	3,256
Gain on sale of investments in marketable securities	0	(3,262)
Deferred rents receivable	(4,369)	(23,237)
Other non-cash adjustments	9,404	20,352
Changes in operating assets and liabilities:
Tenant and other receivables	(397)	1,447
Related party receivables	(1,116)	(7,869)
Deferred lease costs	(17,469)	(23,560)
Other assets	(4,329)	680
Accounts payable, accrued expenses, other liabilities and security deposits	22,867	(11,310)
Deferred revenue and land leases payable	1,121	29,471
Net cash provided by operating activities	246,212	310,850
Investing Activities
Acquisitions of real estate property	(9,733)	(19)
Additions to land, buildings and improvements	(96,577)	(165,262)
Acquisition deposits and deferred purchase price	(1,520)	0
Investments in unconsolidated joint ventures	(254,305)	(93,182)
Distributions in excess of cumulative earnings from unconsolidated joint ventures	178,892	93,688
Net proceeds from disposition of real estate/joint venture interest	760,335	61,248
Proceeds from sale or redemption of marketable securities	0	54,363
Other investments	(22,790)	3,014
Origination of debt and preferred equity investments	(603,575)	(854,577)
Repayments or redemption of debt and preferred equity investments	317,337	663,140
Net cash provided by (used in) investing activities	268,064	(237,587)
Financing Activities
Proceeds from mortgages and other loans payable	210,575	779,642
Repayments of mortgages and other loans payable	(22,864)	(693,243)
Proceeds from revolving credit facility and senior unsecured notes	1,475,000	1,072,800
Repayments of revolving credit facility and senior unsecured notes	(1,155,000)	(875,697)
Proceeds from stock options exercised and DRIP issuance	5,701	11,706
Repurchase of common stock	(724,696)	(211,599)
Redemption of preferred stock	(350)	(125)
Distributions to noncontrolling interests in other partnerships	(724)	(609)
Contributions from noncontrolling interests in other partnerships	1,828	33,009
Dividends / Distributions paid on common and preferred stock / units	(168,411)	(175,790)
Tax withholdings related to restricted share awards	(3,842)	(3,879)
Deferred loan costs and capitalized lease obligation	(1,536)	(8,521)
Net cash used in financing activities	(384,322)	(62,306)
Net increase in cash, cash equivalents, and restricted cash	129,954	10,957
Cash, cash equivalents, and restricted cash at beginning of year	250,026	369,967
Cash, cash equivalents, and restricted cash at end of period	379,980	380,924
Supplemental Disclosure of Non-Cash Investing and Financing Activities:
Conversion of units in the Operating Partnership for common stock	1,560	13,242
Tenant improvements and capital expenditures payable	16,534	7,210
Fair value adjustment to noncontrolling interest in Operating Partnership	4,493	12,712
Deconsolidation of subsidiaries	298,403	328,644
Transfer of assets related to assets held for sale	593,995	173,918
Transfer of liabilities related to assets held for sale	265,538	149
Removal of fully depreciated commercial real estate properties	110,594	5,754
Share repurchase payable	31,605	41,598
Bond repurchase payable	0	65,416
Total cash, cash equivalents, and restricted cash	$ 250,026	$ 369,967