Consolidated Statements of Capital Statement (USD $) Share data in Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2014
Increase (Decrease) in Stockholders' Equity
Other comprehensive income	$ 297,000
DRIP proceeds	15,000
Redemption of units	16,583,000
Deferred compensation plan	(1,425,000)
Amortization of deferred compensation plan	6,713,000
Contributions to consolidated joint venture interest	517,000
Cash distributions to noncontrolling interests	(1,586,000)
Common Stock
Increase (Decrease) in Stockholders' Equity
Redemption of units	2,000
Redemption of units (in units)	(168)
Deferred compensation plan	0
Noncontrolling Interests
Increase (Decrease) in Stockholders' Equity
Contributions to consolidated joint venture interest	517,000
Cash distributions to noncontrolling interests	(1,586,000)
SL Green Operating Partnership
Increase (Decrease) in Stockholders' Equity
Beginning Balance	7,282,352,000
Net income	156,047,000
Other comprehensive income	297,000
Preferred distributions	(3,738,000)
Issuance of units in the Operating Partnership	17,314,000
DRIP proceeds	15,000
Redemption of units	0
Deferred compensation plan	(1,425,000)
Amortization of deferred compensation plan	6,713,000
Contributions to consolidated joint venture interest	517,000
Contributions—net proceeds from common stock offering	24,000
Contributions - proceeds from stock options exercised	8,977,000
Cash distributions to noncontrolling interests	(1,586,000)
Cash distribution declared ($0.50 per common unit, none of which represented a return of capital for federal income tax purposes)	(49,065,000)
Ending Balance	7,416,442,000
SL Green Operating Partnership | General Partner
Increase (Decrease) in Stockholders' Equity
Beginning Balance	6,506,747,000
Balance (shares)	94,993
Net income	146,090,000
DRIP proceeds	15,000
DRIP proceeds (in units)	(168)
Redemption of units	16,583,000
Redemption of units (in units)	0
Deferred compensation plan (shares)	(2)
Deferred compensation plan	(1,425,000)
Amortization of deferred compensation plan	6,713,000
Contributions—net proceeds from common stock offering	24,000
Contributions - net proceeds from common stock offering (in units)	0
Contributions - proceeds from stock options exercised	8,977,000
Contributions - proceeds from stock options exercised (in units)	156
Cash distribution declared ($0.50 per common unit, none of which represented a return of capital for federal income tax purposes)	(47,565,000)
Ending Balance	6,636,159,000
Balance (shares)	95,319
SL Green Operating Partnership | Limited Partners
Increase (Decrease) in Stockholders' Equity
Balance (shares)	2,902
Issuance of units (in units)	235
Redemption of units (in units)	(137)
Deferred compensation plan (shares)
Balance (shares)	3,000
SL Green Operating Partnership | Series I Preferred Stock
Increase (Decrease) in Stockholders' Equity
Beginning Balance	221,932,000
Net income	3,738,000
Preferred distributions	(3,738,000)
Ending Balance	221,932,000
SL Green Operating Partnership | Common Stock | Limited Partners
Increase (Decrease) in Stockholders' Equity
Beginning Balance	77,864,000
Net income	4,729,000
Issuance of units in the Operating Partnership	17,314,000
Redemption of units	(16,583,000)
Cash distribution declared ($0.50 per common unit, none of which represented a return of capital for federal income tax purposes)	(1,500,000)
Ending Balance	81,824,000
SL Green Operating Partnership | Accumulated Other Comprehensive Income (Loss)
Increase (Decrease) in Stockholders' Equity
Beginning Balance	(15,662,000)
Other comprehensive income	297,000
Ending Balance	(15,365,000)
SL Green Operating Partnership | Noncontrolling Interests
Increase (Decrease) in Stockholders' Equity
Beginning Balance	491,471,000
Net income	1,490,000
Contributions to consolidated joint venture interest	517,000
Cash distributions to noncontrolling interests	(1,586,000)
Ending Balance	$ 491,892,000