Consolidated Statements of Cash Flows (Parenthetical) - USD ($) $ in Thousands	1 Months Ended			12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Cash distribution declared, per common share (in dollars per share)	$ 0.3203	$ 0.3217	$ 0.9387	$ 6.2729	$ 4.9374	$ 3.6434
Deconsolidation of a subsidiary				$ 66,837	$ 854,437	$ 395
Stock Distribution
Cash distribution declared, per common share (in dollars per share)	$ 2.5138	$ 1.7996
SL Green Operating Partnership
Cash distribution declared, per common share (in dollars per share)				$ 6.2729	$ 4.9374	$ 3.6434
Deconsolidation of a subsidiary				$ 66,837	$ 854,437	$ 395