Intangible Assets and Liabilities (Details 1) (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Sep. 30, 2013
Acquired Finite-Lived Intangible Assets Liabilities [Line Items]
Acquired finite-lived intangible asset, amount	$ 54,610
Acquired finite-lived intangible liabilities, amount	(4,218)
Below-market rent
Acquired Finite-Lived Intangible Assets Liabilities [Line Items]
Weighted-average useful life, intangible liabilities	33 years 9 months 18 days
Acquired finite-lived intangible liabilities, amount	(4,061)
Above-market ground lease
Acquired Finite-Lived Intangible Assets Liabilities [Line Items]
Weighted-average useful life, intangible liabilities	48 years 7 months 6 days
Acquired finite-lived intangible liabilities, amount	(157)
In-place lease
Acquired Finite-Lived Intangible Assets Liabilities [Line Items]
Weighted average useful life, intangible assets	13 years 10 months 24 days
Acquired finite-lived intangible asset, amount	35,127
Above-market rent
Acquired Finite-Lived Intangible Assets Liabilities [Line Items]
Weighted average useful life, intangible assets	34 years 7 months 6 days
Acquired finite-lived intangible asset, amount	13,769
Below-market ground lease
Acquired Finite-Lived Intangible Assets Liabilities [Line Items]
Weighted average useful life, intangible assets	54 years 7 months 6 days
Acquired finite-lived intangible asset, amount	$ 5,714