Consolidated Statement of Capital shares in Thousands, $ in Thousands	9 Months Ended
	Sep. 30, 2016 USD ($) shares
Increase (Decrease) in Partner's Capital
DRSPP proceeds	$ 146
Conversion of common units	12,746
Reallocation of noncontrolling interests in the operating partnership	(4,959)
Deferred compensation plan and stock award, net	(2,086)
Amortization of deferred compensation plan	19,230
Issuance of common stock	(40)
Contribution to consolidated joint venture interests	2,019
Cash distributions to noncontrolling interests	$ (11,023)
Common Stock
Increase (Decrease) in Partner's Capital
DRSPP proceeds (in shares) | shares	1
Conversion of common units	$ 1
Deferred compensation plan and stock award, net (in shares) | shares	12
Issuance of common stock	$ 10
Contributions - proceeds from stock options exercised (in shares) | shares	157
Noncontrolling Interests
Increase (Decrease) in Partner's Capital
Contribution to consolidated joint venture interests	$ 2,019
Cash distributions to noncontrolling interests	(11,023)
SL Green Operating Partnership
Increase (Decrease) in Partner's Capital
Beginning Balance	7,719,317
Net income	208,388
Other comprehensive (loss)	(5,325)
Preferred distributions	(11,213)
DRSPP proceeds	146
Conversion of common units	12,746
Reallocation of noncontrolling interests in the operating partnership	(4,959)
Deferred compensation plan and stock award, net	(2,086)
Amortization of deferred compensation plan	19,230
Issuance of common stock	(40)
Contribution to consolidated joint venture interests	2,019
Contributions - proceeds from stock options exercised	12,258
Cash distributions to noncontrolling interests	(11,023)
Cash distributions declared ($2.16 per common unit, none of which represented a return of capital for federal income tax purposes)	(216,810)
Ending Balance	7,722,648
SL Green Operating Partnership | Preferred Units
Increase (Decrease) in Partner's Capital
Beginning Balance	221,932
Ending Balance	221,932
SL Green Operating Partnership | Common Stock | Partners' Interest
Increase (Decrease) in Partner's Capital
Beginning Balance	$ 7,074,282
Beginning Balance (units) | shares	99,976
Net income	$ 202,143
Preferred distributions	$ (11,213)
DRSPP proceeds (in shares) | shares	1
DRSPP proceeds	$ 146
Conversion of common units (in shares) | shares	118
Conversion of common units	$ 12,746
Reallocation of noncontrolling interests in the operating partnership	$ (4,959)
Deferred compensation plan and stock award, net (in shares) | shares	12
Deferred compensation plan and stock award, net	$ (2,086)
Amortization of deferred compensation plan	19,230
Issuance of common stock	$ (40)
Contributions - proceeds from stock options exercised (in shares) | shares	157
Contributions - proceeds from stock options exercised	$ 12,258
Cash distributions declared ($2.16 per common unit, none of which represented a return of capital for federal income tax purposes)	(216,810)
Ending Balance	$ 7,085,697
Ending Balance (units) | shares	100,264
SL Green Operating Partnership | Accumulated Other Comprehensive (Loss)
Increase (Decrease) in Partner's Capital
Beginning Balance	$ (8,749)
Other comprehensive (loss)	(5,325)
Ending Balance	(14,074)
SL Green Operating Partnership | Noncontrolling Interests
Increase (Decrease) in Partner's Capital
Beginning Balance	431,852
Net income	6,245
Contribution to consolidated joint venture interests	2,019
Cash distributions to noncontrolling interests	(11,023)
Ending Balance	$ 429,093