Condensed Consolidated Statement Of Stockholders' Equity - 6 months ended Jun. 30, 2016 - USD ($) $ in Thousands	Total	Common Stock [Member]	Additional Paid in Capital [Member]	Accumulated Distributions in Excess of Earnings [Member]	Accumulated Other Comprehensive Loss [Member]	Total Stockholders' Equity [Member]	Noncontrolling Interests [Member]
Balance, (in shares) at Dec. 31, 2015	181,200,952	181,200,952
Balance, at Dec. 31, 2015	$ 1,462,176	$ 1,812	$ 1,591,076	$ (161,798)	$ (2,580)	$ 1,428,510	$ 33,666
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Vesting of restricted stock (in shares)		4,500
Issuance of common stock under the distribution reinvestment plan (in shares)		3,575,588
Issuance of common stock under the distribution reinvestment plan	34,138	$ 36	34,102			34,138	0
Distributions to noncontrolling interests	(1,113)					0	(1,113)
Distributions declared to common stockholders	(63,499)			(63,499)		(63,499)	0
Other offering costs	(9)		(9)			(9)	0
Repurchase of common stock (in shares)		(1,757,973)
Repurchase of common stock	(16,996)	$ (18)	(16,978)			(16,996)	0
Stock-based compensation	45		45			45	0
Other comprehensive loss	(6,469)				(6,469)	(6,469)	0
Net income	$ 36,506			34,517		34,517	1,989
Balance, (in shares) at Jun. 30, 2016	183,023,067	183,023,067
Balance, at Jun. 30, 2016	$ 1,444,779	$ 1,830	$ 1,608,236	$ (190,780)	$ (9,049)	$ 1,410,237	$ 34,542