Noncontrolling Interests on the Company's Consolidated Financial Statements - Preferred Unit Activity (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Rollforward Analysis of Preferred Unit Activity
Redemption of preferred units	$ (29,817)		$ (1,536)
SL Green Operating Partnership
Rollforward Analysis of Preferred Unit Activity
Redemption of preferred units	(29,817)		(1,536)
SL Green Operating Partnership | Preferred Units
Rollforward Analysis of Preferred Unit Activity
Balance at beginning of period	196,075	$ 202,169
Issuance of preferred units	0	0
Redemption of preferred units	(17,967)	(6,040)
Dividends paid on preferred units	(6,198)	(6,760)
Accrued dividends on preferred units	6,033	6,706
Balance at end of period	$ 177,943	$ 196,075	$ 202,169