Noncontrolling Interests on the Company's Consolidated Financial Statements - Schedule of Common Unit Activity (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2024	Dec. 31, 2022
Rollforward Analysis of Preferred Unit Activity
Redemption of preferred units	$ (5,674)
SL Green Operating Partnership
Rollforward Analysis of Preferred Unit Activity
Redemption of preferred units	(5,674)
SL Green Operating Partnership | Preferred stock
Rollforward Analysis of Preferred Unit Activity
Balance at beginning of period	166,501
Issuance of preferred units	0	$ 0
Redemption of preferred units	0	(11,700)
Dividends paid on preferred units	(1,920)	(6,271)
Accrued dividends on preferred units	1,920	6,529
Balance at end of period	$ 166,501	$ 177,943