Consolidated Statements of Operations - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Revenues
Rental revenue, net	$ 416,809,000	$ 304,226,000	$ 762,416,000	$ 607,555,000
Escalation and reimbursement	48,616,000	41,407,000	94,227,000	82,376,000
Investment income	44,214,000	45,191,000	98,951,000	87,260,000
Other income	107,975,000	18,250,000	117,464,000	28,182,000
Total revenues	617,614,000	409,074,000	1,073,058,000	805,373,000
Expenses
Operating expenses, including $6,667 and $10,129 in 2016 and $4,472 and $8,189 in 2015 of related party expenses	75,324,000	70,114,000	154,844,000	146,891,000
Real estate taxes	62,124,000	56,286,000	123,798,000	112,009,000
Ground rent	8,307,000	8,086,000	16,615,000	16,274,000
Interest expense, net of interest income	89,089,000	75,746,000	183,761,000	151,553,000
Amortization of deferred financing costs	7,433,000	5,952,000	15,365,000	12,567,000
Depreciation and amortization	425,042,000	199,565,000	604,350,000	307,902,000
Transaction related costs	2,115,000	3,067,000	3,394,000	4,210,000
Marketing, general and administrative	24,484,000	23,200,000	48,516,000	48,664,000
Total expenses	693,918,000	442,016,000	1,150,643,000	800,070,000
(Loss) 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, gain on sale of real estate, net, depreciable real estate reserves, loss on sale of investment in marketable securities and loss on early extinguishment of debt	(76,304,000)	(32,942,000)	(77,585,000)	5,303,000
Equity in net income from unconsolidated joint ventures	5,841,000	2,994,000	15,937,000	7,024,000
Equity in net gain on sale of interest in unconsolidated joint venture/real estate	33,448,000	769,000	43,363,000	769,000
Gain on sale of real estate, net	196,580,000	0	210,353,000.00	0
Depreciable real estate reserves	(10,387,000)	0	(10,387,000)	0
Loss on sale of investment in marketable securities	(83,000)	0	(83,000)	0
Loss on early extinguishment of debt	0	0	0	(49,000)
Income (loss) from continuing operations	149,095,000	(29,179,000)	181,598,000	13,047,000
Net income (loss) from discontinued operations	0	0	0	427,000
Gain on sale of discontinued operations	0	0	0	12,983,000
Net income (loss)	149,095,000	(29,179,000)	181,598,000	26,457,000
Net income attributable to noncontrolling interests:
Noncontrolling interests in the Operating Partnership	(5,586,000)	1,577,000	(6,508,000)	(166,000)
Net income attributable to noncontrolling interests	(3,435,000)	(6,626,000)	(5,409,000)	(12,553,000)
Preferred units distributions	(2,880,000)	(1,140,000)	(5,528,000)	(2,091,000)
Net income (loss) attributable to SL Green/SLGOP	137,194,000	(35,368,000)	164,153,000	11,647,000
Perpetual preferred stock dividends	(3,737,000)	(3,738,000)	(7,475,000)	(7,476,000)
Amounts attributable to SL Green common stockholders:
(Loss) income from continuing operations before purchase price fair value adjustment, gains on sale and discontinued operations	(77,056,000)	(39,846,000)	(76,947,000)	(9,467,000)
Equity in net gain on sale of interest in unconsolidated joint venture/real estate	32,058,000	740,000	41,634,000	740,000
Net income from discontinued operations	0	0	0	411,000
Gain on sale of discontinued operations	0	0	0	12,487,000
Gain on sale of real estate	188,410,000	0	201,964,000	0
Depreciable real estate reserves	(9,955,000)	0	(9,973,000)	0
Net income (loss) attributable to SL Green common stockholders	$ 133,457,000	$ (39,106,000)	$ 156,678,000	$ 4,171,000
Basic earnings per share:
(Loss) income from continuing operations before purchase price fair value adjustment, gains on sale and discontinued operations (usd per share)	$ (0.77)	$ (0.40)	$ (0.77)	$ (0.10)
Equity in net gain on sale of interest in unconsolidated joint venture/real estate (usd per share)	0.32	0.01	0.42	0.01
Gain on sale of discontinued operations (usd per share)	0.00	0.00	0.00	0.13
Gain on sale of real estate (in dollars per share)	1.88	0.00	2.02	0.00
Depreciable Real Estate Reserves, Effect on Earnings, Per Basic Share	(0.10)	0.00	(0.10)	0.00
Net income attributable to SL Green common stockholders (usd per share)	1.33	(0.39)	1.57	0.04
Diluted earnings per share:
(Loss) income from continuing operations before purchase price fair value adjustment, gains on sale and discontinued operations (usd per share)	(0.77)	(0.40)	(0.77)	(0.10)
Equity in net gain on sale of interest in unconsolidated joint venture/real estate (usd per share)	0.32	0.01	0.42	0.01
Gain on sale of discontinued operations (usd per share)	0.00	0.00	0.00	0.13
Gain on sale of real estate (in dollars per share)	1.88	0.00	2.01	0.00
Depreciable real estate reserves (in dollars per share)	(0.10)	0.00	(0.10)	0.00
Net income attributable to SL Green common stockholders (usd per share)	1.33	(0.39)	1.56	0.04
Dividends per share/unit (usd per share)	$ 0.72	$ 0.60	$ 1.44	$ 1.20
Basic weighted average common shares outstanding (in shares)	100,134,000	99,579,000	100,093,000	98,994,000
Diluted weighted average common shares and common share equivalents outstanding (in shares)	104,792,000	99,579,000	104,533,000	103,423,000
SL Green Operating Partnership
Revenues
Rental revenue, net	$ 416,809,000	$ 304,226,000	$ 762,416,000	$ 607,555,000
Escalation and reimbursement	48,616,000	41,407,000	94,227,000	82,376,000
Investment income	44,214,000	45,191,000	98,951,000	87,260,000
Other income	107,975,000	18,250,000	117,464,000	28,182,000
Total revenues	617,614,000	409,074,000	1,073,058,000	805,373,000
Expenses
Operating expenses, including $6,667 and $10,129 in 2016 and $4,472 and $8,189 in 2015 of related party expenses	75,324,000	70,114,000	154,844,000	146,891,000
Real estate taxes	62,124,000	56,286,000	123,798,000	112,009,000
Ground rent	8,307,000	8,086,000	16,615,000	16,274,000
Interest expense, net of interest income	89,089,000	75,746,000	183,761,000	151,553,000
Amortization of deferred financing costs	7,433,000	5,952,000	15,365,000	12,567,000
Depreciation and amortization	425,042,000	199,565,000	604,350,000	307,902,000
Transaction related costs	2,115,000	3,067,000	3,394,000	4,210,000
Marketing, general and administrative	24,484,000	23,200,000	48,516,000	48,664,000
Total expenses	693,918,000	442,016,000	1,150,643,000	800,070,000
(Loss) 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, gain on sale of real estate, net, depreciable real estate reserves, loss on sale of investment in marketable securities and loss on early extinguishment of debt	(76,304,000)	(32,942,000)	(77,585,000)	5,303,000
Equity in net income from unconsolidated joint ventures	5,841,000	2,994,000	15,937,000	7,024,000
Equity in net gain on sale of interest in unconsolidated joint venture/real estate	33,448,000	769,000	43,363,000	769,000
Gain on sale of real estate, net	196,580,000	0	210,353,000	0
Depreciable real estate reserves	(10,387,000)	0	(10,387,000)	0
Loss on sale of investment in marketable securities	(83,000)	0	(83,000)	0
Loss on early extinguishment of debt	0	0	0	(49,000)
Income (loss) from continuing operations	149,095,000	(29,179,000)	181,598,000	13,047,000
Net income (loss) from discontinued operations	0	0	0	427,000
Gain on sale of discontinued operations	0	0	0	12,983,000
Net income (loss)	149,095,000	(29,179,000)	181,598,000	26,457,000
Net income attributable to noncontrolling interests:
Noncontrolling interests in the Operating Partnership			(6,508,000)
Net income attributable to noncontrolling interests	(3,435,000)	(6,626,000)	(5,409,000)	(12,553,000)
Preferred units distributions	(2,880,000)	(1,140,000)	(5,528,000)	(2,091,000)
Net income (loss) attributable to SL Green/SLGOP	142,780,000	(36,945,000)	170,661,000	11,813,000
Perpetual preferred unit distributions	(3,737,000)	(3,738,000)	(7,475,000)	(7,476,000)
Net income (loss) attributable to SLGOP common unitholders	139,043,000	(40,683,000)	163,186,000	4,337,000
Amounts attributable to SL Green common stockholders:
(Loss) income from continuing operations before purchase price fair value adjustment, gains on sale and discontinued operations	(80,598,000)	(41,452,000)	(80,143,000)	(9,842,000)
Equity in net gain on sale of interest in unconsolidated joint venture/real estate	33,448,000	769,000	43,363,000	769,000
Net income from discontinued operations	0	0	0	427,000
Gain on sale of discontinued operations	0	0	0	12,983,000
Gain on sale of real estate	196,580,000	0	210,353,000	0
Depreciable real estate reserves	(10,387,000)	0	(10,387,000)	0
Net income (loss) attributable to SL Green common stockholders	$ 139,043,000	$ (40,683,000)	$ 163,186,000	$ 4,337,000
Basic earnings per share:
(Loss) income from continuing operations before gains on sale and discontinued operations (usd per share)	$ (0.77)	$ (0.40)	$ (0.77)	$ (0.10)
Equity in net gain on sale of interest in unconsolidated joint venture/real estate (usd per share)	0.32	0.01	0.42	0.01
Net income from discontinued operations (usd per share)	0.00	0.00	0.00	0.00
Gain on sale of discontinued operations (usd per share)	0.00	0.00	0.00	0.13
Gain on sale of real estate (in dollars per share)	1.88	0.00	2.02	0.00
Depreciable Real Estate Reserves, Effect on Earnings, Per Basic Share	(0.10)	0.00	(0.10)	0.00
Net income attributable to SLGOP common unitholders (usd per share)	1.33	(0.39)	1.57	0.04
Diluted earnings per share:
(Loss) income from continuing operations before gains on sale and discontinued operations (in usd per share)	(0.77)	(0.40)	(0.77)	(0.10)
Equity in net gain on sale of interest in unconsolidated joint venture/real estate (usd per share)	0.32	0.01	0.42	0.01
Gain on sale of discontinued operations (usd per share)	0.00	0.00	0.00	0.13
Gain on sale of real estate (in dollars per share)	1.88	0.00	2.01	0.00
Depreciable real estate reserves (in dollars per share)	(0.10)	0.00	(0.10)	0.00
Net income attributable to SLGOP common unitholders (usd per share)	1.33	(0.39)	1.56	0.04
Dividends per share/unit (usd per share)	$ 0.72	$ 0.60	$ 1.44	$ 1.20
Basic weighted average common shares outstanding (in shares)	104,476,000	103,487,000	104,251,000	102,930,000
Basic weighted average common units outstanding (in shares)	104,476	103,487	104,251	102,930
Diluted weighted average common units and common unit equivalents outstanding (in shares)	104,792	103,487	104,533	103,423