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 and Distributions	Total Stockholders’ Equity	Non-controlling Interests, Operating Partnership	Non-controlling Interests, Joint Venture
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	$ 0
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				227			227	(227)
Common stock redemption of common units (in shares)	25,839		25,839
Dividends	$ (69,608)					(69,441)	(69,441)	(167)
Equity-based compensation	5,367		$ 6	5,345			5,351	16
Equity-based compensation (in shares)			620,593
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	$ (146)			(146)			(146)
Other comprehensive loss	6,601				6,582		6,582	19
Net income	85,369					85,165	85,165	204
Balance at end of year at Sep. 30, 2018	1,217,235	$ 94	$ 1,047	1,183,694	8,033	21,648	1,214,516	2,719	0
Balance (in shares) at Sep. 30, 2018		9,400,000	104,745,710
Balance at beginning of year at Jun. 30, 2018	1,198,056	$ 94	$ 1,047	1,182,398	5,545	6,310	1,195,394	2,662	0
Balance (in shares) at Jun. 30, 2018		9,400,000	104,744,101
Changes in equity
Dividends	(22,617)					(22,563)	(22,563)	(54)
Equity-based compensation	1,319			1,315			1,315	4
Equity-based compensation (in shares)			1,609
Other	(19)			(19)			(19)
Other comprehensive loss	2,495				2,488		2,488	7
Net income	38,001					37,901	37,901	100
Balance at end of year at Sep. 30, 2018	1,217,235	$ 94	$ 1,047	1,183,694	8,033	21,648	1,214,516	2,719	0
Balance (in shares) at Sep. 30, 2018		9,400,000	104,745,710
Balance at beginning of year at Dec. 31, 2018	1,192,144	$ 94	$ 1,048	1,185,310	(1,441)	4,838	1,189,849	2,295	0
Balance (in shares) at Dec. 31, 2018		9,400,000	104,783,179
Changes in equity
Contribution by non-controlling interest in joint venture	$ 13,764								13,764
Common stock redemption of common units			$ 1	436	(28)		409	(409)
Common stock redemption of common units (in shares)	46,076		46,076
Dividends	$ (67,243)					(67,103)	(67,103)	(140)
Equity-based compensation	4,766		$ 4	4,751			4,755	11
Equity-based compensation (in shares)			410,432
Shares acquired for employee withholding requirements	$ (839)		$ (1)	(838)			(839)
Shares acquired for employee withholding requirements (in shares)	(74,340)		(74,340)
Other	$ (158)			(158)			(158)
Other comprehensive loss	(18,972)				(18,926)		(18,926)	(46)
Net income	73,595					73,368	73,368	150	77
Balance at end of year at Sep. 30, 2019	1,197,057	$ 94	$ 1,052	1,189,501	(20,395)	11,103	1,181,355	1,861	13,841
Balance (in shares) at Sep. 30, 2019		9,400,000	105,165,347
Balance at beginning of year at Jun. 30, 2019	1,197,057	$ 94	$ 1,051	1,187,715	(16,236)	22,179	1,194,803	2,254	0
Balance (in shares) at Jun. 30, 2019		9,400,000	105,126,626
Changes in equity
Contribution by non-controlling interest in joint venture	13,764								13,764
Common stock redemption of common units			$ 1	383	(28)		356	(356)
Common stock redemption of common units (in shares)			40,000
Dividends	(22,656)					(22,610)	(22,610)	(46)
Equity-based compensation	1,450			1,447			1,447	3
Equity-based compensation (in shares)			(1,279)
Other	(44)			(44)			(44)
Other comprehensive loss	(4,140)				(4,131)		(4,131)	(9)
Net income	11,626					11,534	11,534	15	77
Balance at end of year at Sep. 30, 2019	$ 1,197,057	$ 94	$ 1,052	$ 1,189,501	$ (20,395)	$ 11,103	$ 1,181,355	$ 1,861	$ 13,841
Balance (in shares) at Sep. 30, 2019		9,400,000	105,165,347