Intangible Assets and Liabilities (Details 1) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013
Amortizable intangible assets
Acquired finite-lived intangible asset, amount	$ 4,995
Acquired finite-lived intangible liabilities, amount	(2,394)
In-place lease
Amortizable intangible assets
Weighted average useful life	15 years 0 months 0 days
Acquired finite-lived intangible asset, amount	4,995
Above-market ground lease
Amortizable intangible assets
Weighted average useful life	3 years 3 months 18 days
Acquired finite-lived intangible liabilities, amount	(157)
Below-market rent
Amortizable intangible assets
Weighted average useful life	14 years 4 months 24 days
Acquired finite-lived intangible liabilities, amount	$ (2,237)