Consolidated Statement of Capital - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Increase (Decrease) in Partner's Capital
DRSPP proceeds	$ 89	$ 351
Reallocation of noncontrolling interest in the Operating Partnership	(43,023)	(26,609)
Deferred compensation plan and stock awards, net of forfeitures and tax withholdings	5,056	6,728
Repurchases of common units	(151,197)	(80,310)
Contribution to consolidated joint venture interests		171
Cash distributions to noncontrolling interests	$ (123)	$ (110)
Common Stock
Increase (Decrease) in Partner's Capital
DRSPP proceeds (in shares)	1	5
Deferred compensation plan and stock awards, net of forfeitures and tax withholdings (in shares)	28	110
Deferred compensation plan and stock awards, net of forfeitures and tax withholdings	$ 1	$ 2
Repurchases of common units (in units)	(1,971)	(1,267)
Repurchases of common units	$ (20)	$ (13)
Noncontrolling Interests
Increase (Decrease) in Partner's Capital
Contribution to consolidated joint venture interests		171
Cash distributions to noncontrolling interests	(123)	(110)
Additional Paid- In-Capital
Increase (Decrease) in Partner's Capital
DRSPP proceeds	89	351
Deferred compensation plan and stock awards, net of forfeitures and tax withholdings	5,055	6,726
Repurchases of common units	(114,979)	(80,297)
SL Green Operating Partnership
Increase (Decrease) in Partner's Capital
Beginning Balance	4,778,253	4,935,795
Net income	11,346	(5,225)
Other comprehensive income	39,497	48,350
Preferred distributions	(3,738)	(3,738)
DRSPP proceeds	89	351
Reallocation of noncontrolling interest in the Operating Partnership	(43,023)	(26,609)
Deferred compensation plan and stock awards, net of forfeitures and tax withholdings	5,056	6,728
Repurchases of common units	(151,197)	(80,310)
Contribution to consolidated joint venture interests		171
Cash distributions to noncontrolling interests	(123)	(110)
Issuance of special distribution paid primarily in units	160,620	123,529
Cash distributions declared ($0.932 per common unit, none of which represented a return of capital for federal income tax purposes)	(57,665)	(63,312)
Ending Balance	4,739,115	4,935,620
SL Green Operating Partnership | Preferred Units | Series I Preferred Stock
Increase (Decrease) in Partner's Capital
Beginning Balance	221,932	221,932
Ending Balance	221,932	221,932
SL Green Operating Partnership | Common Stock | Partners' Interest
Increase (Decrease) in Partner's Capital
Beginning Balance	$ 4,589,702	$ 4,755,078
Beginning Balance (units)	64,105	66,474
Net income	$ 11,489	$ (3,726)
Preferred distributions	$ (3,738)	$ (3,738)
DRSPP proceeds (in shares)	1	5
DRSPP proceeds	$ 89	$ 351
Reallocation of noncontrolling interest in the Operating Partnership	$ (43,023)	$ (26,609)
Deferred compensation plan and stock awards, net of forfeitures and tax withholdings (in shares)	28	110
Deferred compensation plan and stock awards, net of forfeitures and tax withholdings	$ 5,056	$ 6,728
Repurchases of common units (in units)	(1,971)	(1,267)
Repurchases of common units	$ (151,197)	$ (80,310)
Issuance of special distribution paid primarily in units (in shares)	1,961	1,974
Issuance of special distribution paid primarily in units	$ 160,620	$ 123,529
Cash distributions declared ($0.932 per common unit, none of which represented a return of capital for federal income tax purposes)	(57,665)	(63,312)
Ending Balance	$ 4,511,333	$ 4,707,991
Ending Balance (units)	64,124	67,296
SL Green Operating Partnership | Accumulated Other Comprehensive Loss
Increase (Decrease) in Partner's Capital
Beginning Balance	$ (46,758)	$ (67,247)
Other comprehensive income	39,497	48,350
Ending Balance	(7,261)	(18,897)
SL Green Operating Partnership | Noncontrolling Interests
Increase (Decrease) in Partner's Capital
Beginning Balance	13,377	26,032
Net income	(143)	(1,499)
Contribution to consolidated joint venture interests		171
Cash distributions to noncontrolling interests	(123)	(110)
Ending Balance	$ 13,111	$ 24,594