Consolidated Statements of Comprehensive (Loss) Income - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024
Statement of Comprehensive Income [Abstract]
Net (loss) income	$ (6,817)	$ 1,959	$ (28,362)	$ 20,348
Other comprehensive (loss) income:
(Decrease) increase in unrealized value of derivative instruments, including SL Green's share of joint venture derivative instruments	(12,584)	(98)	(37,936)	23,116
Increase in unrealized value of marketable securities	303	316	998	1,398
Other comprehensive (loss) income	(12,281)	218	(36,938)	24,514
Comprehensive (loss) income	(19,098)	2,177	(65,300)	44,862
Net (income) loss attributable to noncontrolling interests and preferred units distributions	(538)	(382)	3,670	(1,892)
Other comprehensive loss (income) attributable to noncontrolling interests	799	2	2,418	(1,620)
Comprehensive (loss) income attributable to SL Green	$ (18,837)	$ 1,797	$ (59,212)	$ 41,350