Consolidated Balance Sheets (Parenthetical) (USD $) In Thousands, except Share data, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Tenant and other receivables, allowance (in dollars)	$ 21,652	$ 16,772
Deferred rents receivable, allowance (in dollars)	29,580	29,156
Debt and preferred equity investments, discount (in dollars)	13,572	24,996
Debt and preferred equity investments, allowance (in dollars)	$ 7,000	$ 50,175
SL Green partners' capital, general partner common units outstanding	940	885
SL Green partners' capital, limited partner common units outstanding	90,310	84,897
Limited partner interests in Operating Partnership, limited partner common units outstanding	2,760	2,765
Series H Preferred Units
Preferred Units, liquidation preference (in dollars per unit)	$ 25.00	$ 25.00
Preferred units, issued	80	80
Preferred units, outstanding	80	80
Series C preferred units
Preferred units, outstanding	7,700	11,700
Series D preferred units
Preferred units, outstanding	0	4,000
Series I Preferred Units
Preferred units, outstanding	9,200
Series G Preferred Units
Preferred Units, liquidation preference (in dollars per unit)	$ 25.00
Preferred units, issued	1,902
Preferred units, outstanding	1,902