Organization and Basis of Presentation - Additional Information (Details) ft² in Millions, $ in Millions	1 Months Ended	12 Months Ended
	Jan. 31, 2026 USD ($)	Dec. 31, 2025 ft² building shares	Dec. 31, 2024
Organization
Number of shares to be received on redemption of one unit of limited partnership interests (shares) | shares		1
Park Avenue 500 | Subsequent Event
Organization
Gross asset valuation | $	$ 730.0
January 2025 Mortgage | Park Avenue 500 | Subsequent Event
Organization
Initial Term (in Years)	5 years
Debt instrument, face amount | $	$ 480.0
Interest rate, fixed rate debt (as a percent)	5.30%
Interest rate added to base rate (as a percent)	5.25%
Managed Office Properties
Organization
Approximate square feet | ft²		0.4
Office
Organization
Number of Buildings | building		1
Retail building
Organization
Number of Buildings | building		1
SLG Management LLC | SL Green Management
Organization
Percentage of ownership in SL Green Management LLC owned by operating partnership (percent)		100.00%
Operating Partnership | SL Green Operating Partnership
Organization
Noncontrolling interest in the operating partnership (as a percent)		6.42%	5.97%