Intangible Assets and Liabilities (Details 2) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012
Amortizable intangible assets
Finite-lived intangible assets, gross	$ 556,788	$ 556,978
Less: accumulated amortization	(65,006)	(55,655)
Finite-lived intangible assets, net	491,782	501,323
Amortizable intangible liabilities
Finite-lived intangible liabilities, gross	(86,016)	(84,130)
Less: accumulated amortization	4,704	3,675
Finite Lived Intangible Liabilities, Net	(81,312)	(80,455)
In-place lease
Amortizable intangible assets
Finite-lived intangible assets, gross	469,059	467,846
Less: accumulated amortization	(52,863)	(44,762)
Finite-lived intangible assets, net	416,196	423,084
Above-market ground lease
Amortizable intangible liabilities
Finite-lived intangible liabilities, gross	(157)	0
Less: accumulated amortization	0	0
Finite Lived Intangible Liabilities, Net	(157)	0
Below-market rent
Amortizable intangible liabilities
Finite-lived intangible liabilities, gross	(85,859)	(84,130)
Less: accumulated amortization	4,704	3,675
Finite Lived Intangible Liabilities, Net	(81,155)	(80,455)
Other intangible
Amortizable intangible assets
Finite-lived intangible assets, gross	87,729	89,132
Less: accumulated amortization	(12,143)	(10,893)
Finite-lived intangible assets, net	$ 75,586	$ 78,239