Consolidated Statement of Equity - USD ($) shares in Thousands, $ in Thousands		Total	Cumulative Effect, Period of Adoption, Adjustment	Cumulative Effect, Period of Adoption, Adjusted Balance	Common Stock	Common Stock Cumulative Effect, Period of Adoption, Adjusted Balance	Additional Paid- In-Capital	Additional Paid- In-Capital Cumulative Effect, Period of Adoption, Adjusted Balance	Treasury Stock	Treasury Stock Cumulative Effect, Period of Adoption, Adjusted Balance	Accumulated Other Comprehensive Income (Loss)	Accumulated Other Comprehensive Income (Loss) Cumulative Effect, Period of Adoption, Adjusted Balance	Retained Earnings	Retained Earnings Cumulative Effect, Period of Adoption, Adjustment	Retained Earnings Cumulative Effect, Period of Adoption, Adjusted Balance	Noncontrolling Interests	Noncontrolling Interests Cumulative Effect, Period of Adoption, Adjusted Balance	Series I Preferred Stock Preferred Stock	Series I Preferred Stock Preferred Stock Cumulative Effect, Period of Adoption, Adjusted Balance
Beginning Balance at Dec. 31, 2018		$ 5,947,855			$ 847		$ 4,508,685		$ (124,049)		$ 15,108		$ 1,278,998			$ 46,334		$ 221,932
Beginning Balance (in shares) at Dec. 31, 2018	[1]				78,897
Increase (Decrease) in Stockholders' Equity
Accounting Standards Update		Accounting Standards Update 2016-13
Net income		$ 267,275											270,434			(3,159)
Acquisition of subsidiary interest from noncontrolling interest		(25,845)					(569)									(25,276)
Other comprehensive loss		(43,593)									(43,593)
Preferred dividends		(14,950)											(14,950)
DRSPP (in shares)	[1]				4
DRSPP proceeds		334					334
Conversion of units of the Operating Partnership to common stock (in shares)	[1]				5
Conversion of units in the Operating Partnership for common stock		471					471
Reallocation of noncontrolling interest in the operating partnership		(34,320)											(34,320)
Deferred compensation plan and stock awards, net of forfeitures and tax withholdings (in shares)	[1]				99
Deferred compensation plan and stock awards, net of forfeitures and tax withholdings		25,763			$ 2		25,761
Repurchases of common stock (in shares)	[1]				(4,333)
Repurchases of common units		(384,399)			$ (46)		(248,287)						(136,066)
Contributions to consolidated joint venture interests		58,462														58,462
Cash distributions to noncontrolling interests		(478)														(478)
Cash distributions declared ( per common share, none of which represented a return of capital for federal income tax purposes)		(279,377)											(279,377)
Ending Balance at Dec. 31, 2019		5,517,198	$ (39,184)	$ 5,478,014	$ 803	$ 803	4,286,395	$ 4,286,395	(124,049)	$ (124,049)	(28,485)	$ (28,485)	1,084,719	$ (39,184)	$ 1,045,535	75,883	$ 75,883	221,932	$ 221,932
Ending Balance (in shares) at Dec. 31, 2019	[1]				74,672	74,672
Increase (Decrease) in Stockholders' Equity
Net income		385,995											371,055			14,940
Acquisition of subsidiary interest from noncontrolling interest		(1,536)					(3,123)									1,587
Other comprehensive loss		(38,762)									(38,762)
Preferred dividends		(14,950)											(14,950)
DRSPP (in shares)	[1]				16
DRSPP proceeds		1,006					1,006
Conversion of units of the Operating Partnership to common stock (in shares)	[1]				95
Conversion of units in the Operating Partnership for common stock		8,744			$ 1		8,743
Reallocation of noncontrolling interest in the operating partnership		32,598											32,598
Deferred compensation plan and stock awards, net of forfeitures and tax withholdings (in shares)	[1]				(33)
Deferred compensation plan and stock awards, net of forfeitures and tax withholdings		25,271			$ 0		25,271
Repurchases of common stock (in shares)	[1]				(8,276)
Repurchases of common units		(532,262)			$ (88)		(455,343)						(76,831)
Contributions to consolidated joint venture interests		12,477														12,477
Cash distributions to noncontrolling interests		(78,855)														(78,855)
Cash distributions declared ( per common share, none of which represented a return of capital for federal income tax purposes)		(341,945)											(341,945)
Ending Balance at Dec. 31, 2020		4,935,795			$ 716		3,862,949		(124,049)		(67,247)		1,015,462			26,032		221,932
Ending Balance (in shares) at Dec. 31, 2020	[1]				66,474
Increase (Decrease) in Stockholders' Equity
Net income		447,870											449,754			(1,884)
Other comprehensive loss		20,489									20,489
Preferred dividends		(14,950)											(14,950)
DRSPP (in shares)	[1]				11
DRSPP proceeds		738					738
Reallocation of noncontrolling interest in the operating partnership		(9,851)											(9,851)
Deferred compensation plan and stock awards, net of forfeitures and tax withholdings (in shares)	[1]				108
Deferred compensation plan and stock awards, net of forfeitures and tax withholdings		32,583			$ 2		32,581
Repurchases of common stock (in shares)	[1]				(4,474)
Repurchases of common units		(337,624)			$ (46)		(281,206)						(56,372)
Proceeds from stock options exercised (in shares)	[1]				12
Proceeds from stock options exercised		818					818
Contributions to consolidated joint venture interests		336														336
Sale of interest in partially owned entity		(4,476)														(4,476)
Cash distributions to noncontrolling interests		(6,631)														(6,631)
Issuance of a special dividend paid primarily in stock (in shares)	[1]				1,974
Issuance of special dividend paid primarily in stock		123,529					123,529		(2,111)				2,111
Cash distributions declared ( per common share, none of which represented a return of capital for federal income tax purposes)		(410,373)											(410,373)
Ending Balance at Dec. 31, 2021		$ 4,778,253			$ 672		$ 3,739,409		$ (126,160)		$ (46,758)		$ 975,781			$ 13,377		$ 221,932
Ending Balance (in shares) at Dec. 31, 2021	[1]				64,105

[1] On January 18, 2022, we completed a reverse stock split whereby every 1.03060 SL Green common share was combined into 1 SL Green common share. We have retroactively adjusted the outstanding share counts, share activity, cash distributions declared, and earnings per share, as if the reverse split occurred on December 31, 2018.