Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Assets:
Intangible lease assets, accumulated amortization	$ 98,314	$ 93,012
Tenant receivables, allowance for doubtful accounts	136	83
Deferred lease costs, accumulated amortization	159,518	147,862
Liabilities:
Intangible lease liabilities, accumulated amortization	$ 44,242	$ 42,315
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	145,093,025	145,511,644
Common stock, shares outstanding	145,093,025	145,511,644
Unsecured Debt [Member]
Liabilities:
Discount, premium and unamortized debt issuance costs	$ (12,201)	$ (12,779)
Secured Debt [Member]
Liabilities:
Discount, premium and unamortized debt issuance costs	1,289	1,319
Building and Building Improvements [Member]
Assets:
Buildings and improvements, accumulated depreciation	$ 951,484	$ 922,019