Fair Value Measurements (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Fair Value, Measurements, Recurring [Member] | Estimate of Fair Value, Fair Value Disclosure [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Interest rate swap liability	$ (6,556)	$ (3,236)
Fair Value, Measurements, Recurring [Member] | Fair Value Measurements Using Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Interest rate swap liability	0	0
Fair Value, Measurements, Recurring [Member] | Fair Value Measurements Using Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Interest rate swap liability	(6,556)	(3,236)
Fair Value, Measurements, Recurring [Member] | Fair Value Measurements Using Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Interest rate swap liability	0	0
Fair Value, Measurements, Nonrecurring [Member] | Estimate of Fair Value, Fair Value Disclosure [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired real estate assets	3,327	133,220
Fair Value, Measurements, Nonrecurring [Member] | Fair Value Measurements Using Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired real estate assets	0	0
Fair Value, Measurements, Nonrecurring [Member] | Fair Value Measurements Using Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired real estate assets	0	0
Fair Value, Measurements, Nonrecurring [Member] | Fair Value Measurements Using Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired real estate assets	$ 3,327	$ 133,220