Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013
Operating Activities
Net income	$ 406,943	$ 61,585
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	194,029	173,029
Equity in net income from unconsolidated joint ventures	(14,748)	(1,313)
Distributions of cumulative earnings from unconsolidated joint ventures	14,645	13,467
Equity in net (gain) loss on sale of interest in unconsolidated joint venture interest/real estate	(106,084)	3,583
Purchase price fair value adjustment	71,446	(2,305)
Depreciable real estate reserves	0	2,150
Gain on sale of discontinued operations	(114,735)	(1,113)
Loss on early extinguishment of debt	1,025	10,968
Deferred rents receivable	(26,727)	(29,452)
Other non-cash adjustments	(11,162)	(28,675)
Changes in operating assets and liabilities:
Restricted cash—operations	(4,850)	6,127
Tenant and other receivables	5,890	4,896
Related party receivables	(853)	768
Deferred lease costs	(10,688)	(19,106)
Other assets	(438)	4,075
Accounts payable, accrued expenses and other liabilities and security deposits	12,973	1,793
Deferred revenue and deferred land leases payable	2,788	4,601
Net cash provided by operating activities	276,562	209,688
Investing Activities
Acquisitions of real estate property	(208,614)	(52,534)
Additions to land, buildings and improvements	(134,249)	(61,531)
Escrowed cash—capital improvements/acquisition deposits	(38,227)	(394)
Investments in unconsolidated joint ventures	(170,532)	(81,913)
Distributions in excess of cumulative earnings from unconsolidated joint ventures	157,699	11,117
Net proceeds from disposition of real estate/joint venture interest	258,076	5,852
Proceeds from sale of marketable securities	3,555	190
Purchase of marketable securities	(10,025)	(5,305)
Other investments	20,594	(12,994)
Origination of debt and preferred equity investments	(256,730)	(277,877)
Repayments or redemption of debt and preferred equity investments	60,412	432,667
Net cash used in investing activities	(318,041)	(42,722)
Financing Activities
Proceeds from mortgages and other loans payable	1,601,603	980,333
Repayments of mortgages and other loans payable	(1,496,224)	(833,728)
Proceeds from revolving credit facility, term loan and senior unsecured notes	683,000	370,000
Repayments of revolving credit facility, term loan and senior unsecured notes	(520,690)	(404,970)
Proceeds from stock options exercised and DRIP issuance	19,777	8,995
Net proceeds from sale of common stock	8,750	8,487
Net proceeds from sale of preferred stock	0	(9)
Redemption of preferred stock	0	(192,500)
Distributions to noncontrolling interests in other partnerships	(4,352)	(8,152)
Contributions from noncontrolling interests in other partnerships	1,548	3,364
Distributions to noncontrolling interests in the Operating Partnership	(3,598)	(1,775)
Dividends paid on common and preferred stock	(102,943)	(79,534)
Deferred loan costs and capitalized lease obligation	(43,981)	(8,492)
Net cash provided by (used in) financing activities	142,890	(157,981)
Net increase in cash and cash equivalents	101,411	8,985
Cash and cash equivalents at beginning of period	206,692	189,984
Cash and cash equivalents at end of period	308,103	198,969
Supplemental Disclosure of Non-Cash Investing and Financing Activities:
Issuance of common stock as deferred compensation	1,406	0
Issuance of units in the Operating Partnership	19,460	12,675
Redemption of units in the Operating Partnership	23,066	17,287
Issuance of preferred units of limited partnership interest in the Operating Partnership	4,000	0
Fair value adjustment to noncontrolling interest in the Operating Partnership	107,925	36,091
Derivative instruments at fair value	17,088	479
Tenant improvements and capital expenditures payable	7,192	9,665
Capital leased asset	0	9,992
Transfer to net assets held for sale	339,809	207,665
Transfer to liabilities related to net assets held for sale	193,375	11,894
Transfer of financing receivable to debt investment	19,675	0
Deferred leasing payable	659	4,872
Consolidation of real estate	1,316,591	90,934
Assumption of mortgage loan	0	84,642
SL Green Operating Partnership
Operating Activities
Net income	406,943	61,585
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	194,029	173,029
Equity in net income from unconsolidated joint ventures	(14,748)	(1,313)
Distributions of cumulative earnings from unconsolidated joint ventures	14,645	13,467
Equity in net (gain) loss on sale of interest in unconsolidated joint venture interest/real estate	(106,084)	3,583
Purchase price fair value adjustment	71,446	(2,305)
Depreciable real estate reserves	0	2,150
Gain on sale of discontinued operations	(114,735)	(1,113)
Loss on early extinguishment of debt	1,025	10,968
Deferred rents receivable	(26,727)	(29,452)
Other non-cash adjustments	(11,162)	(28,675)
Changes in operating assets and liabilities:
Restricted cash—operations	(4,850)	6,127
Tenant and other receivables	5,890	4,896
Related party receivables	(853)	768
Deferred lease costs	(10,688)	(19,106)
Other assets	(438)	4,075
Accounts payable, accrued expenses and other liabilities and security deposits	12,973	1,793
Deferred revenue and deferred land leases payable	2,788	4,601
Net cash provided by operating activities	276,562	209,688
Investing Activities
Acquisitions of real estate property	(208,614)	(52,534)
Additions to land, buildings and improvements	(134,249)	(61,531)
Escrowed cash—capital improvements/acquisition deposits	(38,227)	(394)
Investments in unconsolidated joint ventures	(170,532)	(81,913)
Distributions in excess of cumulative earnings from unconsolidated joint ventures	157,699	11,117
Net proceeds from disposition of real estate/joint venture interest	258,076	5,852
Proceeds from sale of marketable securities	3,555	190
Purchase of marketable securities	(10,025)	(5,305)
Other investments	20,594	(12,994)
Origination of debt and preferred equity investments	(256,730)	(277,877)
Repayments or redemption of debt and preferred equity investments	60,412	432,667
Net cash used in investing activities	(318,041)	(42,722)
Financing Activities
Proceeds from mortgages and other loans payable	1,601,603	980,333
Repayments of mortgages and other loans payable	(1,496,224)	(833,728)
Proceeds from revolving credit facility, term loan and senior unsecured notes	683,000	370,000
Repayments of revolving credit facility, term loan and senior unsecured notes	(520,690)	(404,970)
Proceeds from stock options exercised and DRIP issuance	19,777	8,995
Net proceeds from sale of common stock	8,750	8,487
Net proceeds from sale of preferred stock	0	(9)
Redemption of preferred stock	0	(192,500)
Distributions to noncontrolling interests in other partnerships	(4,352)	(8,152)
Contributions from noncontrolling interests in other partnerships	1,548	3,364
Dividends paid on common and preferred stock	(106,541)	(81,309)
Deferred loan costs and capitalized lease obligation	(43,981)	(8,492)
Net cash provided by (used in) financing activities	142,890	(157,981)
Net increase in cash and cash equivalents	101,411	8,985
Cash and cash equivalents at beginning of period	206,692	189,984
Cash and cash equivalents at end of period	308,103	198,969
Supplemental Disclosure of Non-Cash Investing and Financing Activities:
Issuance of common stock as deferred compensation	1,406	0
Issuance of units in the Operating Partnership	19,460	12,675
Redemption of units in the Operating Partnership	23,066	17,287
Issuance of preferred units of limited partnership interest in the Operating Partnership	4,000	0
Derivative instruments at fair value	17,088	479
Tenant improvements and capital expenditures payable	7,192	9,665
Capital leased asset	0	9,992
Transfer to net assets held for sale	339,809	207,665
Transfer to liabilities related to net assets held for sale	193,375	11,894
Transfer of financing receivable to debt investment	19,675	0
Deferred leasing payable	659	4,872
Consolidation of real estate	1,316,591	90,934
Assumption of mortgage loan	$ 0	$ 84,642