Noncontrolling Interests on the Company's Consolidated Financial Statements - Additional Information (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Rollforward analysis of the activity relating to the noncontrolling interests in the operating partnership
Distributions	$ (3,126)	$ (11,053)	$ (2,777)
Acquisition of subsidiary interest from noncontrolling interest	(15,631)	(9,216)
Net income (loss)	(7,673)	497	(37,465)
Accumulated other comprehensive income (loss) allocation	$ (2,804)	$ 151	(1,960)
SL Green Operating Partnership
Organization
Number of units of operating partnership owned by the noncontrolling interest unit holders (shares)	4,877,891	4,509,953
Rollforward analysis of the activity relating to the noncontrolling interests in the operating partnership
Distributions	$ (3,126)	$ (11,053)	(2,777)
Accumulated other comprehensive income (loss) allocation	$ (2,804)	$ 151	(1,960)
SL Green Operating Partnership | Operating Partnership
Organization
Noncontrolling interest in the operating partnership (as a percent)	6.42%	5.97%
SL Green Operating Partnership | Series A Preferred Units
Rollforward analysis of the activity relating to the noncontrolling interests in the operating partnership
Stated Distribution Rate	6.00%
Preferred Units, shares authorized (in shares)	109,161
Number of preferred units issued (in shares)	109,161
Preferred units, shares outstanding (in shares)	109,161
Annual dividends on preferred units (in dollars per share)	$ 60.0000
Liquidation preference of preferred units (in dollars per share)	1,000
Conversion Price Per Unit (in dollars per share)	$ 0
SL Green Operating Partnership | Series F
Rollforward analysis of the activity relating to the noncontrolling interests in the operating partnership
Stated Distribution Rate	7.00%
Preferred Units, shares authorized (in shares)	60
Number of preferred units issued (in shares)	60
Preferred units, shares outstanding (in shares)	60
Annual dividends on preferred units (in dollars per share)	$ 70.0000
Liquidation preference of preferred units (in dollars per share)	1,000
Conversion Price Per Unit (in dollars per share)	$ 29.12
SL Green Operating Partnership | Series K
Rollforward analysis of the activity relating to the noncontrolling interests in the operating partnership
Stated Distribution Rate	3.50%
Preferred Units, shares authorized (in shares)	700,000
Number of preferred units issued (in shares)	563,954
Preferred units, shares outstanding (in shares)	341,677
Annual dividends on preferred units (in dollars per share)	$ 0.8750
Liquidation preference of preferred units (in dollars per share)	25.00
Conversion Price Per Unit (in dollars per share)	$ 134.67
SL Green Operating Partnership | Series L
Rollforward analysis of the activity relating to the noncontrolling interests in the operating partnership
Stated Distribution Rate	4.00%
Preferred Units, shares authorized (in shares)	500,000
Number of preferred units issued (in shares)	378,634
Preferred units, shares outstanding (in shares)	272,783
Annual dividends on preferred units (in dollars per share)	$ 1.0000
Liquidation preference of preferred units (in dollars per share)	25.00
Conversion Price Per Unit (in dollars per share)	$ 0
SL Green Operating Partnership | Series R
Rollforward analysis of the activity relating to the noncontrolling interests in the operating partnership
Stated Distribution Rate	3.50%
Preferred Units, shares authorized (in shares)	400,000
Number of preferred units issued (in shares)	400,000
Preferred units, shares outstanding (in shares)	400,000
Annual dividends on preferred units (in dollars per share)	$ 0.8750
Liquidation preference of preferred units (in dollars per share)	25.00
Conversion Price Per Unit (in dollars per share)	$ 154.89
SL Green Operating Partnership | Series S
Rollforward analysis of the activity relating to the noncontrolling interests in the operating partnership
Stated Distribution Rate	4.00%
Preferred Units, shares authorized (in shares)	1,077,280
Number of preferred units issued (in shares)	1,077,280
Preferred units, shares outstanding (in shares)	1,077,280
Annual dividends on preferred units (in dollars per share)	$ 1.0000
Liquidation preference of preferred units (in dollars per share)	25.00
Conversion Price Per Unit (in dollars per share)	$ 0
SL Green Operating Partnership | Series V Preferred Stock
Rollforward analysis of the activity relating to the noncontrolling interests in the operating partnership
Stated Distribution Rate	5.00%
Preferred Units, shares authorized (in shares)	40,000
Number of preferred units issued (in shares)	40,000
Preferred units, shares outstanding (in shares)	40,000
Annual dividends on preferred units (in dollars per share)	$ 1.2500
Liquidation preference of preferred units (in dollars per share)	25.00
Conversion Price Per Unit (in dollars per share)	$ 0
SL Green Operating Partnership | Series W
Rollforward analysis of the activity relating to the noncontrolling interests in the operating partnership
Preferred Units, shares authorized (in shares)	1
Number of preferred units issued (in shares)	1
Preferred units, shares outstanding (in shares)	1
Preferred stock, dividend, multiplier per common unit distribution	1,350
Partnership Interest
Rollforward analysis of the activity relating to the noncontrolling interests in the operating partnership
Balance at beginning of year	$ 288,941	$ 238,051
Distributions	(14,162)	(13,915)
Issuance of common units	19,531	20,790
Acquisition of subsidiary interest from noncontrolling interest	(22,302)	(28,663)
Net income (loss)	(7,673)	497
Accumulated other comprehensive income (loss) allocation	(2,804)	151
Fair value adjustment	(20,160)	72,030
Balance at end of year	$ 241,371	$ 288,941	$ 238,051