Condensed Consolidated Statements of Changes in Equity - USD ($) $ in Thousands	Total	Preferred Stock	Common Stock	Additional Paid-In Capital	Accumulated Other Comprehensive Loss	Accumulated Deficit and Distributions	Total Stockholders’ Equity	Non-controlling Interests in Operating Partnership
Balance at beginning of year at Dec. 31, 2014	$ 785,201	$ 84	$ 861	$ 888,191	$ (1,746)	$ (107,779)	$ 779,611	$ 5,590
Balance (in shares) at Dec. 31, 2014		8,400,000	86,149,720
Changes in equity
Common stock redemption of common units			$ 1	666			667	(667)
Common stock redemption of common units (in shares)	114,947		114,947
Dividends paid	$ (28,755)					(28,587)	(28,587)	(168)
Equity-based compensation	2,008		$ 3	1,988			1,991	17
Equity-based compensation (in shares)			308,310
Other	(453)			(453)			(453)
Other (in shares)			(36,385)
Other comprehensive loss	(296)				(294)		(294)	(2)
Net income	26,892					26,738	26,738	154
Balance at end of year at Jun. 30, 2015	784,597	$ 84	$ 865	890,392	(2,040)	(109,628)	779,673	4,924
Balance (in shares) at Jun. 30, 2015		8,400,000	86,536,592
Balance at beginning of year at Dec. 31, 2015	856,926	$ 84	$ 868	894,060	(1,666)	(40,635)	852,711	4,215
Balance (in shares) at Dec. 31, 2015		8,400,000	86,793,521
Changes in equity
Net proceeds from sale of preferred stock	$ 72,337	$ 30		72,307			72,337
Net proceeds from sale of preferred stock (in shares)		3,000,000
Common stock redemption of common units			$ 0	447			447	(447)
Common stock redemption of common units (in shares)	53,636		53,636
Dividends paid	$ (30,280)					(30,162)	(30,162)	(118)
Equity-based compensation	2,182		$ 5	2,165			2,170	12
Equity-based compensation (in shares)			482,127
Other	(717)			(717)			(717)
Other (in shares)			(61,622)
Other comprehensive loss	(647)				(643)		(643)	(4)
Net income	70,689					70,350	70,350	339
Balance at end of year at Jun. 30, 2016	$ 970,490	$ 114	$ 873	$ 968,262	$ (2,309)	$ (447)	$ 966,493	$ 3,997
Balance (in shares) at Jun. 30, 2016		11,400,000	87,267,662