Stockholders' Equity of the Company (Details 3) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Basic Earnings:
Net income attributable to SL Green common stockholders	$ 146,090	$ 18,909
Diluted Earnings:
Income attributable to SLGOP common unitholders	150,819	19,464
Basic Shares:
Basic weighted average common shares outstanding (in shares)	95,117,000	91,399,000
Effect of Dilutive Securities:
Redemption of units to common shares (shares)	3,079,000	2,687,000
Stock-based compensation plans (in shares)	520,000	216,000
Diluted weighted average common stock outstanding (shares)	98,716,000	94,302,000
Common stock shares excluded from the diluted shares outstanding	860,720	988,887
Common Stock
Effect of Dilutive Securities:
Redemption of units to common shares	$ 4,729	$ 555