Consolidated Statements of Comprehensive (Loss) Income - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Statement of Comprehensive Income [Abstract]
Net income (loss)	$ 18,389	$ (38,357)
Other comprehensive income (loss):
Increase (decrease) in unrealized value of derivative instruments, including SL Green's share of joint venture derivative instruments	23,214	(31,059)
Increase (decrease) in unrealized value of marketable securities	1,082	(968)
Other comprehensive income (loss)	24,296	(32,027)
Comprehensive income (loss)	42,685	(70,384)
Net (income) loss attributable to noncontrolling interests and preferred units distributions	(1,510)	2,364
Other comprehensive (income) loss attributable to noncontrolling interests	(1,622)	1,851
Comprehensive income (loss) attributable to SL Green	$ 39,553	$ (66,169)