Consolidated Statements of Equity - USD ($) $ in Thousands	Total	Preferred Shares	Common Shares	Additional Paid-In Capital	Accumulated Other Comprehensive Income (Loss)	Distributions in Excess of Retained Earnings	Total Shareholders' Equity	Non-Controlling Interests
Preferred stock, beginning balance (in shares) at Dec. 31, 2017		10,000,000
Common stock, beginning balance (in shares) at Dec. 31, 2017			68,812,575
Beginning balance at Dec. 31, 2017	$ 1,503,526	$ 100	$ 688	$ 1,685,437	$ 3,689	$ (191,013)	$ 1,498,901	$ 4,625
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common shares for Board of Trustees compensation (in shares)			17,410
Issuance of common shares for Board of Trustees compensation	662		$ 1	661			662
Repurchase of common shares (in shares)			(69,687)
Repurchase of common shares	(2,507)		$ (1)	(2,506)			(2,507)
Share-based compensation (in shares)			151,887
Share-based compensation	1,599		$ 1	1,046			1,047	552
Distributions on common shares/units	(52,684)					(52,504)	(52,504)	(180)
Distributions on preferred shares	(8,063)					(8,047)	(8,047)	(16)
Other comprehensive income (loss):
Unrealized gain (loss) on derivative instruments	7,290				7,290		7,290
Other	0
Net income (loss)	82,811					82,512	82,512	299
Preferred stock, ending balance (in shares) at Jun. 30, 2018		10,000,000
Common stock, ending balance (in shares) at Jun. 30, 2018			68,912,185
Ending balance at Jun. 30, 2018	1,532,634	$ 100	$ 689	1,684,638	11,527	(169,600)	1,527,354	5,280
Preferred stock, beginning balance (in shares) at Mar. 31, 2018		10,000,000
Common stock, beginning balance (in shares) at Mar. 31, 2018			68,912,185
Beginning balance at Mar. 31, 2018	1,500,330	$ 100	$ 689	1,683,046	8,936	(197,359)	1,495,412	4,918
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Share-based compensation	1,868			(1,592)			1,592	276
Distributions on common shares/units	(26,410)					(26,320)	(26,320)	(90)
Distributions on preferred shares	(4,040)					(4,024)	(4,024)	(16)
Other comprehensive income (loss):
Unrealized gain (loss) on derivative instruments	2,012				2,012		2,012
Other	579				579		579
Net income (loss)	58,295					58,103	58,103	192
Preferred stock, ending balance (in shares) at Jun. 30, 2018		10,000,000
Common stock, ending balance (in shares) at Jun. 30, 2018			68,912,185
Ending balance at Jun. 30, 2018	$ 1,532,634	$ 100	$ 689	1,684,638	11,527	(169,600)	1,527,354	5,280
Preferred stock, beginning balance (in shares) at Dec. 31, 2018	20,400,000	20,400,000
Common stock, beginning balance (in shares) at Dec. 31, 2018	130,311,289		130,311,289
Beginning balance at Dec. 31, 2018	$ 3,769,930	$ 204	$ 1,303	4,065,804	1,330	(308,806)	3,759,835	10,095
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of shares, net of offering costs	(275)			(275)			(275)
Issuance of common shares for Board of Trustees compensation (in shares)			25,282
Issuance of common shares for Board of Trustees compensation	740		$ 1	739			740
Repurchase of common shares (in shares)			(126,681)
Repurchase of common shares	(4,009)		$ (1)	(4,008)			(4,009)
Share-based compensation (in shares)			275,066
Share-based compensation	3,966		$ 2	3,412			3,414	552
Distributions on common shares/units	(99,845)					(99,539)	(99,539)	(306)
Distributions on preferred shares	(16,278)					(16,278)	(16,278)
Other comprehensive income (loss):
Unrealized gain (loss) on derivative instruments	(30,128)				(30,128)		(30,128)
Other	0
Net income (loss)	$ 66,173					66,008	66,008	165
Preferred stock, ending balance (in shares) at Jun. 30, 2019	20,400,000	20,400,000
Common stock, ending balance (in shares) at Jun. 30, 2019	130,484,956		130,484,956
Ending balance at Jun. 30, 2019	$ 3,690,274	$ 204	$ 1,305	4,065,672	(28,798)	(358,615)	3,679,768	10,506
Preferred stock, beginning balance (in shares) at Mar. 31, 2019		20,400,000
Common stock, beginning balance (in shares) at Mar. 31, 2019			130,484,956
Beginning balance at Mar. 31, 2019	3,706,799	$ 204	$ 1,305	4,063,830	(7,709)	(361,081)	3,696,549	10,250
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Share-based compensation	2,118			1,842			1,842	276
Distributions on common shares/units	(49,933)					(49,768)	(49,768)	(165)
Distributions on preferred shares	(8,139)					(8,139)	(8,139)
Other comprehensive income (loss):
Unrealized gain (loss) on derivative instruments	(21,089)				(21,089)		(21,089)
Other	0
Net income (loss)	$ 60,518					60,373	60,373	145
Preferred stock, ending balance (in shares) at Jun. 30, 2019	20,400,000	20,400,000
Common stock, ending balance (in shares) at Jun. 30, 2019	130,484,956		130,484,956
Ending balance at Jun. 30, 2019	$ 3,690,274	$ 204	$ 1,305	$ 4,065,672	$ (28,798)	$ (358,615)	$ 3,679,768	$ 10,506