Condensed Consolidated Statements of Changes in Equity (Unaudited) - USD ($) $ in Thousands	Total	Preferred Stock	Common Stock	Additional Paid-In Capital	Accumulated Other Comprehensive Loss	Retained Earnings (Deficit) and Distributions	Total Stockholders’ Equity	Non-controlling Interests in Operating Partnership
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 common and preferred stock	$ 72,337	$ 30		72,307			72,337
Net proceeds from sale of common and preferred stock (in shares)	0	3,000,000
Common stock redemption of common units				447			447	(447)
Common stock redemption of common units (in shares)	53,636		53,636
Dividends	$ (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
Shares acquired to satisfy employee withholding requirements	$ (717)			(717)			(717)
Shares acquired to satisfy employee withholding requirements (in shares)	(61,622)		(61,622)
Other comprehensive income	$ (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
Balance at beginning of year at Dec. 31, 2016	1,013,470	$ 94	$ 935	1,011,412	(977)	(1,422)	1,010,042	3,428
Balance (in shares) at Dec. 31, 2016		9,400,000	93,525,469
Changes in equity
Net proceeds from sale of common and preferred stock	$ 163,670		$ 104	163,566			163,670
Net proceeds from sale of common and preferred stock (in shares)	10,350,000		10,350,000
Common stock redemption of common units			$ 0	268			268	(268)
Common stock redemption of common units (in shares)	30,657		30,657
Dividends	$ (41,441)					(41,315)	(41,315)	(126)
Equity-based compensation	2,994		$ 4	2,978			2,982	12
Equity-based compensation (in shares)			391,792
Shares acquired to satisfy employee withholding requirements	$ (961)		$ (1)	(960)			(961)
Shares acquired to satisfy employee withholding requirements (in shares)	(59,111)		(59,111)
Other comprehensive income	$ 523				521		521	2
Net income	67,289					67,055	67,055	234
Balance at end of year at Jun. 30, 2017	$ 1,205,544	$ 94	$ 1,042	$ 1,177,264	$ (456)	$ 24,318	$ 1,202,262	$ 3,282
Balance (in shares) at Jun. 30, 2017		9,400,000	104,238,807