Consolidated Balance Sheets (Parenthetical) (USD $) In Thousands, except Share data, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013
Assets:
Intangible lease assets, accumulated amortization	$ 69,997	$ 71,588
Tenant receivables, allowance for doubtful accounts	273	346
Deferred financing costs, accumulated amortization	4,506	13,041
Deferred lease costs, accumulated amortization	123,582	125,882
Liabilities:
Discount on debt	4,703	1,320
Intangible lease liabilities, accumulated amortization	44,462	44,256
Stockholders’ Equity:
Shares-in-trust, shares authorized	150,000,000	150,000,000
Shares-in-trust, shares outstanding	0	0
Preferred stock, par value (in dollars per share)	$ 0	$ 0
Preferred stock, shares authorized	100,000,000	100,000,000
Preferred stock, shares outstanding	0	0
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized	750,000,000	750,000,000
Common stock, shares issued	154,277,930	157,460,903
Common stock, shares outstanding	154,277,930	157,460,903
Building and Building Improvements [Member]
Assets:
Buildings and improvements, accumulated depreciation	$ 997,350	$ 972,531