Noncontrolling Interests on the Company's Consolidated Financial Statements - Preferred Units of Limited Partnership Interest (Details) - SL Green Operating Partnership	12 Months Ended
	Dec. 31, 2025 $ / shares shares
Series A Preferred Stock
Preferred Units [Line Items]
Stated Distribution Rate	6.00%
Preferred Units, shares authorized (in shares)	109,161
Preferred units, shares issued (in shares)	109,161
Preferred units, shares outstanding (in shares)	109,161
Annual dividends on preferred units (in dollars per share) | $ / shares	$ 60.0000
Preferred units, liquidation preference (in dollars per share) | $ / shares	1,000
Conversion Price Per Unit (in dollars per share) | $ / shares	$ 0
Series F
Preferred Units [Line Items]
Stated Distribution Rate	7.00%
Preferred Units, shares authorized (in shares)	60
Preferred units, shares issued (in shares)	60
Preferred units, shares outstanding (in shares)	60
Annual dividends on preferred units (in dollars per share) | $ / shares	$ 70.0000
Preferred units, liquidation preference (in dollars per share) | $ / shares	1,000
Conversion Price Per Unit (in dollars per share) | $ / shares	$ 29.12
Series K
Preferred Units [Line Items]
Stated Distribution Rate	3.50%
Preferred Units, shares authorized (in shares)	700,000
Preferred units, shares issued (in shares)	563,954
Preferred units, shares outstanding (in shares)	341,677
Annual dividends on preferred units (in dollars per share) | $ / shares	$ 0.8750
Preferred units, liquidation preference (in dollars per share) | $ / shares	25.00
Conversion Price Per Unit (in dollars per share) | $ / shares	$ 134.67
Series L
Preferred Units [Line Items]
Stated Distribution Rate	4.00%
Preferred Units, shares authorized (in shares)	500,000
Preferred units, shares issued (in shares)	378,634
Preferred units, shares outstanding (in shares)	272,783
Annual dividends on preferred units (in dollars per share) | $ / shares	$ 1.0000
Preferred units, liquidation preference (in dollars per share) | $ / shares	25.00
Conversion Price Per Unit (in dollars per share) | $ / shares	$ 0
Series R
Preferred Units [Line Items]
Stated Distribution Rate	3.50%
Preferred Units, shares authorized (in shares)	400,000
Preferred units, shares issued (in shares)	400,000
Preferred units, shares outstanding (in shares)	400,000
Annual dividends on preferred units (in dollars per share) | $ / shares	$ 0.8750
Preferred units, liquidation preference (in dollars per share) | $ / shares	25.00
Conversion Price Per Unit (in dollars per share) | $ / shares	$ 154.89
Series S
Preferred Units [Line Items]
Stated Distribution Rate	4.00%
Preferred Units, shares authorized (in shares)	1,077,280
Preferred units, shares issued (in shares)	1,077,280
Preferred units, shares outstanding (in shares)	1,077,280
Annual dividends on preferred units (in dollars per share) | $ / shares	$ 1.0000
Preferred units, liquidation preference (in dollars per share) | $ / shares	25.00
Conversion Price Per Unit (in dollars per share) | $ / shares	$ 0
Series V
Preferred Units [Line Items]
Stated Distribution Rate	5.00%
Preferred Units, shares authorized (in shares)	40,000
Preferred units, shares issued (in shares)	40,000
Preferred units, shares outstanding (in shares)	40,000
Annual dividends on preferred units (in dollars per share) | $ / shares	$ 1.2500
Preferred units, liquidation preference (in dollars per share) | $ / shares	25.00
Conversion Price Per Unit (in dollars per share) | $ / shares	$ 0
Series W
Preferred Units [Line Items]
Preferred Units, shares authorized (in shares)	1
Preferred units, shares issued (in shares)	1
Preferred units, shares outstanding (in shares)	1
Preferred stock, dividend, multiplier per common unit distribution	1,350
Series X
Preferred Units [Line Items]
Stated Distribution Rate	3.00%
Preferred Units, shares authorized (in shares)	172,809
Preferred units, shares issued (in shares)	172,809
Preferred units, shares outstanding (in shares)	172,809
Annual dividends on preferred units (in dollars per share) | $ / shares	$ 0.7500
Preferred units, liquidation preference (in dollars per share) | $ / shares	25.00
Conversion Price Per Unit (in dollars per share) | $ / shares	$ 80.00