Noncontrolling Interests on the Company's Consolidated Financial Statements - Common Unit Activity (Details) - SL Green Operating Partnership - Series I Preferred Units - USD ($) $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 30, 2023	Dec. 31, 2022
Rollforward Analysis of Preferred Unit Activity
Balance at beginning of period	$ 177,943	$ 196,075
Issuance of preferred units	0	0
Redemption of preferred units	(11,700)	(17,967)
Dividends paid on preferred units	(2,893)	(6,198)
Accrued dividends on preferred units	3,151	6,033
Balance at end of period	$ 166,501	$ 177,943