Condensed Consolidated Statements of Changes in Equity (Unaudited) - USD ($) $ in Thousands	Total	Preferred Stock	Common Stock	Additional Paid-In Capital	Accumulated Other Comprehensive Income (Loss)	Retained Earnings (Deficit) and Distributions	Total Stockholders’ Equity	Non-controlling Interests in Operating Partnership
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 stock	$ 163,670		$ 104	163,566			163,670
Net proceeds from sale of common stock (in shares)	10,350,000		10,350,000
Common stock redemption of common units				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 for employee withholding requirements	$ (961)		$ (1)	(960)			(961)
Shares acquired for 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
Balance at beginning of year at Dec. 31, 2017	$ 1,277,376	$ 128	$ 1,043	1,262,679	1,451	9,201	1,274,502	2,874
Balance (in shares) at Dec. 31, 2017		12,800,000	104,287,128
Changes in equity
Net proceeds from sale of common stock (in shares)	0
Redemption of preferred stock	$ (85,000)	$ (34)		(81,689)		(3,277)	(85,000)
Redemption of preferred stock (in shares)		(3,400,000)
Common stock redemption of common units				227			227	(227)
Common stock redemption of common units (in shares)	25,839		25,839
Dividends	$ (46,991)					(46,878)	(46,878)	(113)
Equity-based compensation	4,048		$ 6	4,030			4,036	12
Equity-based compensation (in shares)			618,984
Shares acquired for employee withholding requirements	$ (2,724)		$ (2)	(2,722)			(2,724)
Shares acquired for employee withholding requirements (in shares)	(187,850)		(187,850)
Other	$ (127)			(127)			(127)
Other comprehensive income	4,106				4,094		4,094	12
Net income	47,368					47,264	47,264	104
Balance at end of year at Jun. 30, 2018	$ 1,198,056	$ 94	$ 1,047	$ 1,182,398	$ 5,545	$ 6,310	$ 1,195,394	$ 2,662
Balance (in shares) at Jun. 30, 2018		9,400,000	104,744,101