Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Revenues
Rental revenue, net	$ 983,557	$ 978,574	$ 1,273,932
Investment income	195,590	201,492	193,871
Other income	59,848	47,326	43,670
Total revenues	1,238,995	1,227,392	1,511,473
Expenses
Operating expenses, including $18,106 in 2019, $17,823 in 2018, $21,400 in 2017 of related party expenses	234,676	229,347	293,364
Real estate taxes	190,764	186,351	244,323
Operating lease rent	33,188	32,965	33,231
Interest expense, net of interest income	190,521	208,669	257,045
Amortization of deferred financing costs	11,653	12,408	16,498
Depreciation and amortization	272,358	279,507	403,320
Loan loss and other investment reserves, net of recoveries	0	6,839	0
Transaction related costs	729	1,099	(1,834)
Marketing, general and administrative	100,875	92,631	100,498
Total expenses	1,034,764	1,049,816	1,346,445
Equity in net (loss) income from unconsolidated joint ventures	(34,518)	7,311	21,892
Equity in net gain on sale of interest in unconsolidated joint venture/real estate	76,181	303,967	16,166
Purchase price and other fair value adjustment	69,389	57,385	0
(Loss) gain on sale of real estate, net	(16,749)	(30,757)	73,241
Depreciable real estate reserves and impairment	(7,047)	(227,543)	(178,520)
Gain on sale of investment in marketable securities	0	0	3,262
Loss on early extinguishment of debt	0	(17,083)	0
Net income	291,487	270,856	101,069
Net (income) loss attributable to noncontrolling interests:
Noncontrolling interests in the Operating Partnership	(13,301)	(12,216)	(3,995)
Net loss attributable to noncontrolling interests in other partnerships	3,159	6	15,701
Preferred unit distributions	(10,911)	(11,384)	(11,401)
Net income (loss) attributable to SL Green/SLGOP	270,434	247,262	101,374
Perpetual preferred stock dividends	(14,950)	(14,950)	(14,950)
Net income attributable to SL Green common stockholders	$ 255,484	$ 232,312	$ 86,424
Basic weighted average common shares outstanding (in shares)	81,733	86,753	98,571
Diluted weighted average common shares and common share equivalents outstanding (in shares)	86,562	91,530	103,403
SL Green Operating Partnership
Revenues
Rental revenue, net	$ 983,557	$ 978,574	$ 1,273,932
Investment income	195,590	201,492	193,871
Other income	59,848	47,326	43,670
Total revenues	1,238,995	1,227,392	1,511,473
Expenses
Operating expenses, including $18,106 in 2019, $17,823 in 2018, $21,400 in 2017 of related party expenses	234,676	229,347	293,364
Real estate taxes	190,764	186,351	244,323
Operating lease rent	33,188	32,965	33,231
Interest expense, net of interest income	190,521	208,669	257,045
Amortization of deferred financing costs	11,653	12,408	16,498
Depreciation and amortization	272,358	279,507	403,320
Loan loss and other investment reserves, net of recoveries	0	6,839	0
Transaction related costs	729	1,099	(1,834)
Marketing, general and administrative	100,875	92,631	100,498
Total expenses	1,034,764	1,049,816	1,346,445
Equity in net (loss) income from unconsolidated joint ventures	(34,518)	7,311	21,892
Equity in net gain on sale of interest in unconsolidated joint venture/real estate	76,181	303,967	16,166
Purchase price and other fair value adjustment	69,389	57,385	0
(Loss) gain on sale of real estate, net	(16,749)	(30,757)	73,241
Depreciable real estate reserves and impairment	(7,047)	(227,543)	(178,520)
Gain on sale of investment in marketable securities	0	0	3,262
Loss on early extinguishment of debt	0	(17,083)	0
Net income	291,487	270,856	101,069
Net (income) loss attributable to noncontrolling interests:
Net loss attributable to noncontrolling interests in other partnerships	3,159	6	15,701
Preferred unit distributions	(10,911)	(11,384)	(11,401)
Net income (loss) attributable to SL Green/SLGOP	283,735	259,478	105,369
Perpetual preferred stock dividends	(14,950)	(14,950)	(14,950)
Net income attributable to SLGOP common unitholders	$ 268,785	$ 244,528	$ 90,419
Basic earnings per unit (in dollars per share)	$ 3.10	$ 2.67	$ 0.87
Diluted earnings per unit (in dollars per share)	$ 3.10	$ 2.67	$ 0.87
Basic weighted average common shares outstanding (in shares)	86,008	91,315	103,127
Basic weighted average common units outstanding (in shares)	86,008	91,315	103,127
Diluted weighted average common shares and common share equivalents outstanding (in shares)	86,562	91,530	103,403
Diluted weighted average common units and common unit equivalents outstanding (in shares)	86,562	91,530	103,403