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
Common stock redemption of common units				92			92	(92)
Common stock redemption of common units (in shares)	10,657		10,657
Dividends	$ (19,460)					(19,396)	(19,396)	(64)
Equity-based compensation	1,130		$ 3	1,122			1,125	5
Equity-based compensation (in shares)			317,401
Shares acquired for employee withholding requirements	$ (688)			(688)			(688)
Shares acquired to satisfy employee withholding requirements (in shares)	(42,355)		(42,355)
Other comprehensive income	$ 349				348		348	1
Net income	33,206					33,086	33,086	120
Balance at end of year at Mar. 31, 2017	1,028,007	$ 94	$ 938	1,011,938	(629)	12,268	1,024,609	3,398
Balance (in shares) at Mar. 31, 2017		9,400,000	93,811,172
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
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 (in shares)	0
Dividends	$ (24,380)					(24,322)	(24,322)	(58)
Equity-based compensation	2,227		$ 6	2,214			2,220	7
Equity-based compensation (in shares)			584,520
Shares acquired for employee withholding requirements	$ (2,724)		$ (2)	(2,722)			(2,724)
Shares acquired to satisfy employee withholding requirements (in shares)	(187,850)		(187,850)
Other	$ (61)			(61)			(61)
Other comprehensive income	3,744				3,732		3,732	12
Net income	9,691					9,688	9,688	3
Balance at end of year at Mar. 31, 2018	$ 1,180,873	$ 94	$ 1,047	$ 1,180,421	$ 5,183	$ (8,710)	$ 1,178,035	$ 2,838
Balance (in shares) at Mar. 31, 2018		9,400,000	104,683,798