Noncontrolling Interests on the Company's Consolidated Financial Statements - Common Unit Activity (Details) - SL Green Operating Partnership - Preferred Units - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2022	Dec. 31, 2021
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	(1,662)	(6,760)
Accrued dividends on preferred units	1,497	6,706
Balance at end of period	$ 177,943	$ 196,075