Consolidated Statements of Operations (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Revenues
Rental revenue, net	$ 211,369	$ 279,407	$ 426,738	$ 560,736
Escalation and reimbursement	27,052	42,620	53,451	86,812
Investment income	49,273	60,622	94,563	100,921
Other income	13,422	15,501	28,059	27,062
Total revenues	301,116	398,150	602,811	775,531
Expenses
Operating expenses, including related party expenses of $4,665 and $8,499 in 2018 and $5,262 and $9,436 in 2017, respectively.	56,237	70,852	116,019	145,358
Real estate taxes	45,322	60,945	90,983	122,013
Ground rent	8,846	8,308	17,154	16,616
Interest expense, net of interest income	53,611	64,856	101,527	130,478
Amortization of deferred financing costs	3,546	3,432	7,083	8,193
Depreciation and amortization	67,914	133,054	137,302	227,188
Transaction related costs	348	46	510	179
Marketing, general and administrative	22,479	24,256	46,007	48,399
Total expenses	258,303	365,749	516,585	698,424
Net income 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 and other fair value adjustments, (loss) gain on sale of real estate net, depreciable real estate reserves, and gain on sale of marketable securities	42,813	32,401	86,226	77,107
Equity in net income from unconsolidated joint ventures	4,702	3,412	8,738	10,026
Equity in net gain on sale of interest in unconsolidated joint venture/real estate	72,025	13,089	65,585	15,136
Purchase price and other fair value adjustments	11,149	0	60,442	0
(Loss) gain on sale of real estate, net	(14,790)	(3,823)	8,731	(3,256)
Depreciable real estate reserves	0	(29,064)	0	(85,336)
Gain on sale of investment in marketable securities	0	0	0	3,262
Net income	115,899	16,015	229,722	16,939
Net (income) loss attributable to noncontrolling interests:
Noncontrolling interests in the Operating Partnership	(5,586)	(419)	(10,858)	(895)
Noncontrolling interests in other partnerships	(173)	(786)	(371)	16,705
Preferred units distributions	(2,847)	(2,851)	(5,696)	(5,701)
Net income (loss) attributable to SL Green/SLGOP	107,293	11,959	212,797	27,048
Perpetual preferred stock dividends	(3,737)	(3,737)	(7,475)	(7,475)
Amounts attributable to SL Green common stockholders:
Income before depreciable real estate reserves and gains on sale and fair value adjustments	38,674	27,156	77,333	89,818
Purchase price and other fair value adjustments	10,578	0	57,406	0
Equity in net gain on sale of interest in unconsolidated joint venture/real estate	68,336	12,517	62,291	14,474
(Loss) gain on sale of real estate, net	(14,032)	(3,656)	8,292	(3,114)
Depreciable real estate reserves	0	(27,795)	0	(81,605)
Net income attributable to SL Green common stockholders	$ 103,556	$ 8,222	$ 205,322	$ 19,573
Basic earnings per share:
Income (loss) before depreciable real estate reserves and gains (losses) on sale (in dollars per share)	$ 0.44	$ 0.27	$ 0.87	$ 0.90
Purchase price and other fair value adjustments (in dollars per share)	0.12	0.00	0.65	0.00
Equity in net gain on sale of interest in unconsolidated joint venture/real estate (in dollars per share)	0.79	0.13	0.70	0.14
Gain on sale of real estate, net (in dollars per share)	(0.16)	(0.04)	0.09	(0.03)
Depreciable real estate reserves (in dollars per share)	0.00	(0.28)	0.00	(0.81)
Net income attributable to SL Green common stockholders (usd per share)	1.19	0.08	2.31	0.20
Diluted earnings per share:
Purchase price and other fair value adjustments (in dollars per share)	0.12	0.00	0.65	0.00
Income (loss) before depreciable real estate reserves and gains (losses) on sale (in dollars per share)	0.44	0.27	0.87	0.89
Equity in net gain on sale of interest in unconsolidated joint venture/real estate (in dollars per share)	0.79	0.12	0.70	0.14
Gain on sale of real estate (in dollars per share)	(0.16)	(0.04)	0.09	(0.03)
Depreciable real estate reserves (in dollars per share)	0.00	(0.27)	0.00	(0.81)
Net income attributable to SL Green common stockholders (usd per share)	1.19	0.08	2.31	0.19
Dividends per share/unit (usd per share)	$ 0.8125	$ 0.775	$ 1.625	$ 1.55
Basic weighted average common shares outstanding (in shares)	87,176	99,900	88,772	100,268
Diluted weighted average common shares and common share equivalents outstanding (in shares)	92,083	104,732	93,667	105,140
SL Green Operating Partnership
Revenues
Rental revenue, net	$ 211,369	$ 279,407	$ 426,738	$ 560,736
Escalation and reimbursement	27,052	42,620	53,451	86,812
Investment income	49,273	60,622	94,563	100,921
Other income	13,422	15,501	28,059	27,062
Total revenues	301,116	398,150	602,811	775,531
Expenses
Operating expenses, including related party expenses of $4,665 and $8,499 in 2018 and $5,262 and $9,436 in 2017, respectively.	56,237	70,852	116,019	145,358
Real estate taxes	45,322	60,945	90,983	122,013
Ground rent	8,846	8,308	17,154	16,616
Interest expense, net of interest income	53,611	64,856	101,527	130,478
Amortization of deferred financing costs	3,546	3,432	7,083	8,193
Depreciation and amortization	67,914	133,054	137,302	227,188
Transaction related costs	348	46	510	179
Marketing, general and administrative	22,479	24,256	46,007	48,399
Total expenses	258,303	365,749	516,585	698,424
Net income 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 and other fair value adjustments, (loss) gain on sale of real estate net, depreciable real estate reserves, and gain on sale of marketable securities	42,813	32,401	86,226	77,107
Equity in net income from unconsolidated joint ventures	4,702	3,412	8,738	10,026
Equity in net gain on sale of interest in unconsolidated joint venture/real estate	72,025	13,089	65,585	15,136
Purchase price and other fair value adjustments	11,149	0
(Loss) gain on sale of real estate, net	(14,790)	(3,823)	8,731	(3,256)
Depreciable real estate reserves	0	(29,064)	0	(85,336)
Gain on sale of investment in marketable securities	0	0	0	3,262
Net income	115,899	16,015	229,722	16,939
Net (income) loss attributable to noncontrolling interests:
Noncontrolling interests in the Operating Partnership			(10,858)
Noncontrolling interests in other partnerships	(173)	(786)	(371)	16,705
Preferred units distributions	(2,847)	(2,851)	(5,696)	(5,701)
Net income (loss) attributable to SL Green/SLGOP	112,879	12,378	223,655	27,943
Perpetual preferred unit distributions	(3,737)	(3,737)	(7,475)	(7,475)
Net income attributable to SLGOP common unitholders	109,142	8,641	216,180	20,468
Amounts attributable to SL Green common stockholders:
Income before depreciable real estate reserves and gains on sale and fair value adjustments	40,758	28,439	81,422	93,924
Purchase price and other fair value adjustments	11,149	0	60,442	0
Equity in net gain on sale of interest in unconsolidated joint venture/real estate	72,025	13,089	65,585	15,136
(Loss) gain on sale of real estate, net	(14,790)	(3,823)	8,731	(3,256)
Depreciable real estate reserves	$ 0	$ (29,064)	$ 0	$ (85,336)
Basic earnings per share:
Income (loss) before depreciable real estate reserves and gains (losses) on sale (in dollars per share)	$ 0.44	$ 0.27	$ 0.87	$ 0.90
Purchase price and other fair value adjustments (in dollars per share)	0.12	0.00	0.65	0.00
Equity in net gain on sale of interest in unconsolidated joint venture/real estate (in dollars per share)	0.79	0.13	0.70	0.14
Gain on sale of real estate, net (in dollars per share)	(0.16)	(0.04)	0.09	(0.03)
Depreciable real estate reserves (in dollars per share)	0.00	(0.28)	0.00	(0.81)
Net income attributable to SLGOP common unitholders (usd per share)	1.19	0.08	2.31	0.20
Diluted earnings per share:
Income (loss) before depreciable real estate reserves and gains (losses) on sale (in dollars per share)	0.44	0.27	0.87	0.89
Purchase price and other fair value adjustments (in dollars per share)	0.12	0.00	0.65	0.00
Equity in net gain on sale of interest in unconsolidated joint venture/real estate (in dollars per share)	0.79	0.12	0.70	0.14
Gain on sale of real estate (in dollars per share)	(0.16)	(0.04)	0.09	(0.03)
Depreciable real estate reserves (in dollars per share)	0.00	(0.27)	0.00	(0.81)
Net income attributable to SLGOP common unitholders (usd per share)	1.19	0.08	2.31	0.19
Dividends per share/unit (usd per share)	$ 0.8125	$ 0.775	$ 1.625	$ 1.55
Basic weighted average common shares outstanding (in shares)	91,882	104,462	93,467	104,852
Basic weighted average common units outstanding (in shares)	91,882	104,462	93,467	104,852
Diluted weighted average common units and common unit equivalents outstanding (in shares)	92,083	104,732	93,667	105,140