Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Revenues
Rental revenue, net	$ 1,245,981	$ 1,121,066	$ 996,782
Escalation and reimbursement	178,512	164,376	155,965
Investment income	181,128	178,815	193,843
Other income	57,208	55,721	24,475
Total revenues	1,662,829	1,519,978	1,371,065
Expenses
Operating expenses, including $20,071 in 2015, $19,308 in 2014, and $19,152 in 2013 of related party expenses	301,624	282,283	276,589
Real estate taxes	232,702	217,843	203,076
Ground rent	32,834	32,307	31,951
Interest expense, net of interest income	323,870	317,400	310,894
Amortization of deferred financing costs	27,348	22,377	15,855
Depreciation and amortization	560,887	371,610	324,461
Transaction related costs	11,430	8,707	3,985
Marketing, general and administrative	94,873	92,488	86,192
Total expenses	1,585,568	1,345,015	1,253,003
Income from continuing operations before equity in net income from unconsolidated joint ventures, equity in net gain on sale of interest in unconsolidated joint venture/real estate, purchase price fair value adjustment, gain on sale of real estate, depreciable real estate reserves, gain (loss) on sale of marketable securities and loss on early extinguishment of debt	77,261	174,963	118,062
Equity in net income from unconsolidated joint ventures	13,028	26,537	9,921
Equity in net gain on sale of interest in unconsolidated joint venture/real estate	15,844	123,253	3,601
Purchase price fair value adjustment	40,078	67,446	(2,305)
Gain on sale of real estate, net	175,974	0	0
Depreciable real estate reserves	(19,226)	0	0
Gain (loss) on sale of investment in marketable securities	0	3,895	(65)
Loss on early extinguishment of debt	(49)	(32,365)	(18,518)
Income from continuing operations	302,910	363,729	110,696
Net income from discontinued operations	427	19,075	25,687
Gain on sale of discontinued operations	14,122	163,059	14,900
Net income	317,459	545,863	151,283
Net income attributable to noncontrolling interests:
Noncontrolling interests in the Operating Partnership	(10,565)	(18,467)	(3,023)
Net income attributable to noncontrolling interests in other partnerships	(15,843)	(6,590)	(10,629)
Preferred unit distributions	(6,967)	(2,750)	(2,260)
Net income (loss) attributable to SL Green/SLGOP	284,084	518,056	135,371
Preferred stock/unit redemption costs	0	0	(12,160)
Perpetual preferred stock dividends	(14,952)	(14,952)	(21,881)
Amounts attributable to SL Green common stockholders:
Income from continuing operations before purchase price fair value adjustment, gains on sale and discontinued operations	50,502	143,466	60,654
Purchase price fair value adjustment	38,563	65,059	(2,239)
Equity in net gain on sale of interest in unconsolidated joint venture/real estate	15,245	118,891	3,497
Net income from discontinued operations	411	18,400	24,947
Gain on sale of discontinued operations	13,588	157,288	14,471
Gain on sale of real estate	169,322	0	0
Depreciable real estate reserves	(18,499)	0	0
Net income attributable to SL Green common stockholders	$ 269,132	$ 503,104	$ 101,330
Basic earnings per share:
Income from continuing operations before purchase price fair value adjustment, gains on sale and discontinued operations (usd per share)	$ 0.51	$ 1.50	$ 0.66
Purchase price fair value adjustment (usd per share)	0.39	0.68	(0.02)
Equity in net gain on sale of interest in unconsolidated joint venture/real estate (usd per share)	0.15	1.24	0.04
Net income from discontinued operations (usd per share)	0.00	0.19	0.27
Gain on sale of discontinued operations (usd per share)	0.14	1.64	0.15
Gain on sale of real estate (in dollars per share)	1.71	0.00	0.00
Depreciable real estate reserves (in dollars per share)	(0.19)	0.00	0.00
Net income attributable to SL Green common stockholders (usd per share)	2.71	5.25	1.10
Diluted earnings per share:
Income from continuing operations before purchase price fair value adjustment, gains on sale and discontinued operations (usd per share)	0.51	1.52	0.66
Purchase price fair value adjustment (usd per share)	0.39	0.65	(0.03)
Equity in net gain on sale of interest in unconsolidated joint venture/real estate (usd per share)	0.15	1.24	0.04
Net income from discontinued operations (usd per share)	0.00	0.19	0.27
Gain on sale of discontinued operations (usd per share)	0.14	1.63	0.16
Gain on sale of real estate (in dollars per share)	1.70	0.00	0.00
Depreciable real estate reserves (in dollars per share)	(0.19)	0.00	0.00
Net income attributable to SL Green common stockholders (usd per share)	2.70	5.23	1.10
Dividends per share/unit (usd per share)	$ 2.52	$ 2.10	$ 1.49
Basic weighted average common shares outstanding (in shares)	99,345	95,774	92,269
Diluted weighted average common shares and common share equivalents outstanding (in shares)	103,734	99,696	95,266
SL Green Operating Partnership
Revenues
Rental revenue, net	$ 1,245,981	$ 1,121,066	$ 996,782
Escalation and reimbursement	178,512	164,376	155,965
Investment income	181,128	178,815	193,843
Other income	57,208	55,721	24,475
Total revenues	1,662,829	1,519,978	1,371,065
Expenses
Operating expenses, including $20,071 in 2015, $19,308 in 2014, and $19,152 in 2013 of related party expenses	301,624	282,283	276,589
Real estate taxes	232,702	217,843	203,076
Ground rent	32,834	32,307	31,951
Interest expense, net of interest income	323,870	317,400	310,894
Amortization of deferred financing costs	27,348	22,377	15,855
Depreciation and amortization	560,887	371,610	324,461
Transaction related costs	11,430	8,707	3,985
Marketing, general and administrative	94,873	92,488	86,192
Total expenses	1,585,568	1,345,015	1,253,003
Income from continuing operations before equity in net income from unconsolidated joint ventures, equity in net gain on sale of interest in unconsolidated joint venture/real estate, purchase price fair value adjustment, gain on sale of real estate, depreciable real estate reserves, gain (loss) on sale of marketable securities and loss on early extinguishment of debt	77,261	174,963	118,062
Equity in net income from unconsolidated joint ventures	13,028	26,537	9,921
Equity in net gain on sale of interest in unconsolidated joint venture/real estate	15,844	123,253	3,601
Purchase price fair value adjustment	40,078	67,446	(2,305)
Gain on sale of real estate, net	175,974	0	0
Depreciable real estate reserves	(19,226)	0	0
Gain (loss) on sale of investment in marketable securities	0	3,895	(65)
Loss on early extinguishment of debt	(49)	(32,365)	(18,518)
Income from continuing operations	302,910	363,729	110,696
Net income from discontinued operations	427	19,075	25,687
Gain on sale of discontinued operations	14,122	163,059	14,900
Net income	317,459	545,863	151,283
Net income attributable to noncontrolling interests:
Net income attributable to noncontrolling interests in other partnerships	(15,843)	(6,590)	(10,629)
Preferred unit distributions	(6,967)	(2,750)	(2,260)
Net income (loss) attributable to SL Green/SLGOP	294,649	536,523	138,394
Preferred stock/unit redemption costs	0	0	(12,160)
Perpetual preferred unit distributions	(14,952)	(14,952)	(21,881)
Net income attributable to SLGOP common unitholders	279,697	521,571	104,353
Amounts attributable to SL Green common stockholders:
Income from continuing operations before purchase price fair value adjustment, gains on sale and discontinued operations	52,478	148,738	62,470
Purchase price fair value adjustment	40,078	67,446	(2,305)
Equity in net gain on sale of interest in unconsolidated joint venture/real estate	15,844	123,253	3,601
Net income from discontinued operations	427	19,075	25,687
Gain on sale of discontinued operations	14,122	163,059	14,900
Gain on sale of real estate	175,974	0	0
Depreciable real estate reserves	$ (19,226)	$ 0	$ 0
Basic earnings per share:
Income from continuing operations before gains on sale and discontinued operations (usd per share)	$ 0.51	$ 1.50	$ 0.66
Purchase price fair value adjustment (usd per share)	0.39	0.68	(0.02)
Equity in net gain on sale of interest in unconsolidated joint venture/real estate (usd per share)	0.15	1.24	0.04
Net income from discontinued operations (usd per share)	0.00	0.19	0.27
Gain on sale of discontinued operations (usd per share)	0.14	1.64	0.15
Gain on sale of real estate (in dollars per share)	1.71	0.00	0.00
Depreciable real estate reserves (in dollars per share)	(0.19)	0.00	0.00
Net income attributable to SLGOP common unitholders (usd per share)	2.71	5.25	1.10
Diluted earnings per share:
Income from continuing operations before gains on sale and discontinued operations (usd per share)	0.51	1.52	0.66
Purchase price fair value adjustment (usd per share)	0.39	0.65	(0.03)
Equity in net gain on sale of interest in unconsolidated joint venture/real estate (usd per share)	0.15	1.24	0.04
Net income from discontinued operations (usd per share)	0.00	0.19	0.27
Gain on sale of discontinued operations (usd per share)	0.14	1.63	0.16
Gain on sale of real estate (in dollars per share)	1.70	0.00	0.00
Depreciable real estate reserves (in dollars per share)	(0.19)	0.00	0.00
Net income attributable to SLGOP common unitholders (usd per share)	2.70	5.23	1.10
Dividends per share/unit (usd per share)	$ 2.52	$ 2.10	$ 1.49
Basic weighted average common units outstanding (in shares)	103,244	99,288	95,004
Diluted weighted average common units and common unit equivalents outstanding (in shares)	103,734	99,696	95,266