Financial Instruments: Derivatives and Hedging - Schedule of Notional and Fair Value of Derivative Financial Instruments and Foreign Currency Hedges (Details) - USD ($) $ in Thousands	Sep. 30, 2025	Dec. 31, 2024
Financial Instruments: Derivatives and Hedging
Fair Value	$ 8,964	$ 31,860
Interest Rate Contract
Financial Instruments: Derivatives and Hedging
Fair Value	(8,580)
January 2026
Financial Instruments: Derivatives and Hedging
Notional Value	$ 150,000
Strike Rate	2.621%
Fair Value	$ 514
January 2026
Financial Instruments: Derivatives and Hedging
Notional Value	$ 200,000
Strike Rate	2.662%
Fair Value	$ 665
June 2026
Financial Instruments: Derivatives and Hedging
Notional Value	$ 72,314
Strike Rate	4.00%
Fair Value	$ (19)
December 2026
Financial Instruments: Derivatives and Hedging
Notional Value	$ 125,000
Strike Rate	3.667%
Fair Value	$ (265)
December 2026
Financial Instruments: Derivatives and Hedging
Notional Value	$ 125,000
Strike Rate	3.67%
Fair Value	$ (273)
February 2027
Financial Instruments: Derivatives and Hedging
Notional Value	$ 100,000
Strike Rate	2.903%
Fair Value	$ 741
February 2027
Financial Instruments: Derivatives and Hedging
Notional Value	$ 100,000
Strike Rate	2.733%
Fair Value	$ 965
February 2027
Financial Instruments: Derivatives and Hedging
Notional Value	$ 50,000
Strike Rate	2.463%
Fair Value	$ 661
February 2027
Financial Instruments: Derivatives and Hedging
Notional Value	$ 200,000
Strike Rate	2.591%
Fair Value	$ 2,307
May 2027
Financial Instruments: Derivatives and Hedging
Notional Value	$ 300,000
Strike Rate	2.866%
Fair Value	$ 2,526
May 2027
Financial Instruments: Derivatives and Hedging
Notional Value	$ 150,000
Strike Rate	3.524%
Fair Value	$ (288)
June 2027
Financial Instruments: Derivatives and Hedging
Notional Value	$ 370,000
Strike Rate	3.888%
Fair Value	$ (3,068)
June 2027
Financial Instruments: Derivatives and Hedging
Notional Value	$ 68,678
Strike Rate	4.466%
Fair Value	$ (1,259)
November 2027
Financial Instruments: Derivatives and Hedging
Notional Value	$ 300,000
Strike Rate	4.487%
Fair Value	$ (6,974)
January 2028
Financial Instruments: Derivatives and Hedging
Notional Value	$ 100,000
Strike Rate	3.756%
Fair Value	$ (940)
February 2028
Financial Instruments: Derivatives and Hedging
Notional Value	$ 80,000
Strike Rate	4.174%
Fair Value	$ (1,497)
May 2028
Financial Instruments: Derivatives and Hedging
Notional Value	$ 204,663
Strike Rate	3.915%
Fair Value	$ (2,961)
June 2028
Financial Instruments: Derivatives and Hedging
Notional Value	$ 357,500
Strike Rate	2.982%
Fair Value	$ 585

SL GREEN REALTY CORP 10-Q