Consolidated Statements of Comprehensive Income (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Consolidated Statements of Comprehensive Income
Net income	$ 209,700	$ 677,122	$ 319,156
Other comprehensive income (loss):
Net unrealized gain (loss) on derivative instruments	953	(4,145)	(3,938)
SL Green's share of joint venture net unrealized gain on derivative instruments	1,174	799	269
Unrealized gain (loss) on marketable securities	(3,657)	(2,731)	13,487
Other comprehensive income (loss)	(1,530)	(6,077)	9,818
Comprehensive income	208,170	671,045	328,974
Net income attributable to noncontrolling interests	(13,295)	(29,712)	(18,581)
Other comprehensive loss attributable to noncontrolling interests	388	291	1,061
Preferred stock redemption costs	(10,010)
Comprehensive income attributable to SL Green	$ 185,253	$ 641,624	$ 311,454