Partners' Capital of the Operating Partnership - Additional Information (Details) - shares	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Stockholders' Equity
Units, outstanding (in units)	71,158,530
Shares, issued (in shares)	71,158,530
Preferred stock, shares outstanding (in shares)	9,200,000	9,200,000
Series I Preferred Units
Stockholders' Equity
Preferred stock, shares outstanding (in shares)	9,200,000
Common Stock
Stockholders' Equity
Units, outstanding (in units)	71,159,000	71,097,000	64,726,000	64,380,000
SL Green Operating Partnership
Stockholders' Equity
Units, outstanding (in units)	71,158,530
Shares, issued (in shares)	71,158,530
Number of units of operating partnership owned by the noncontrolling interest unit holders (units)	4,877,891	4,509,953
SL Green Operating Partnership | Operating Partnership
Stockholders' Equity
Noncontrolling interest in the operating partnership (as a percent)	6.42%	5.97%
SL Green Operating Partnership | Series I Preferred Units
Stockholders' Equity
Common units redemption, period of restriction	1 year
Conversion of stock, shares issued (in shares)	1