Consolidated Statement of Capital shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2017 USD ($) shares
Increase (Decrease) in Partner's Capital
DRSPP proceeds	$ 56
Conversion of common units	13,112
Reallocation of noncontrolling interests in the operating partnership	(15,548)
Deferred compensation plan and stock award, net	(1,963)
Amortization of deferred compensation plan	6,691
Contribution to consolidated joint venture interests	31,947
Cash distributions to noncontrolling interests	$ (469)
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	(10)
Contributions - proceeds from stock options exercised (in shares) | shares	104
Noncontrolling Interests
Increase (Decrease) in Partner's Capital
Contribution to consolidated joint venture interests	$ 31,947
Cash distributions to noncontrolling interests	(469)
SL Green Operating Partnership
Increase (Decrease) in Partner's Capital
Beginning Balance	7,750,911
Net income (loss)	(2,402)
Other comprehensive loss	(5,626)
Preferred distributions	(3,738)
DRSPP proceeds	56
Conversion of common units	13,112
Reallocation of noncontrolling interests in the operating partnership	(15,548)
Deferred compensation plan and stock award, net	(1,963)
Amortization of deferred compensation plan	6,691
Contribution to consolidated joint venture interests	31,947
Contributions - proceeds from stock options exercised	8,752
Cash distributions to noncontrolling interests	(469)
Cash distributions declared ($0.775 per common unit, none of which represented a return of capital for federal income tax purposes)	(77,937)
Ending Balance	7,703,684
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	$ 7,080,406
Beginning Balance (units) | shares	100,562
Net income (loss)	$ 15,089
Preferred distributions	$ (3,738)
DRSPP proceeds (in shares) | shares	1
DRSPP proceeds	$ 56
Conversion of common units (in shares) | shares	120
Conversion of common units	$ 13,112
Reallocation of noncontrolling interests in the operating partnership	$ (15,548)
Deferred compensation plan and stock award, net (in shares) | shares	(10)
Deferred compensation plan and stock award, net	$ (1,963)
Amortization of deferred compensation plan	$ 6,691
Contributions - proceeds from stock options exercised (in shares) | shares	104
Contributions - proceeds from stock options exercised	$ 8,752
Cash distributions declared ($0.775 per common unit, none of which represented a return of capital for federal income tax purposes)	(77,937)
Ending Balance	$ 7,024,818
Ending Balance (units) | shares	100,776
SL Green Operating Partnership | Accumulated Other Comprehensive Income (Loss)
Increase (Decrease) in Partner's Capital
Beginning Balance	$ 22,137
Other comprehensive loss	(5,626)
Ending Balance	16,511
SL Green Operating Partnership | Noncontrolling Interests
Increase (Decrease) in Partner's Capital
Beginning Balance	426,436
Net income (loss)	(17,491)
Contribution to consolidated joint venture interests	31,947
Cash distributions to noncontrolling interests	(469)
Ending Balance	$ 440,423