CONDENSED CONSOLIDATED STATEMENTS OF SHAREHOLDERS' EQUITY - USD ($) $ in Thousands	Total	Common Shares	Additional Paid-in Capital	Cumulative Net Income	Cumulative Other Comprehensive Income (Loss)	Cumulative Distributions	Total Equity Attributable to Common Shareholders	Total Equity Attributable to Noncontrolling Interest
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cumulative adjustment upon adoption of ASU No. 2016-01	$ 0			$ 87,429	$ (87,429)
Adjusted balance	3,277,188	$ 2,376	$ 4,609,316	1,853,924	(198)	$ (3,360,468)	$ 3,104,950	$ 172,238
Beginning balance (in shares) at Dec. 31, 2017		237,630,409
Beginning balance at Dec. 31, 2017	3,277,188	$ 2,376	4,609,316	1,766,495	87,231	(3,360,468)	3,104,950	172,238
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net (loss) income	237,405			236,022			236,022	1,383
Other Comprehensive Income (Loss), Net of Tax	(93)				(93)		(93)
Distributions	(92,674)					(92,674)	(92,674)
Share grants (in shares)		3,000
Share grants	47		47				47
Share repurchases (in shares)		(4,628)
Share repurchases	(89)		(89)				(89)
Distributions to noncontrolling interest	(5,667)							(5,667)
Ending balance (in shares) at Mar. 31, 2018		237,628,781
Ending balance at Mar. 31, 2018	3,416,117	$ 2,376	4,609,274	2,089,946	(291)	(3,453,142)	3,248,163	167,954
Beginning balance (in shares) at Dec. 31, 2017		237,630,409
Beginning balance at Dec. 31, 2017	3,277,188	$ 2,376	4,609,316	1,766,495	87,231	(3,360,468)	3,104,950	172,238
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net (loss) income	362,393
Other Comprehensive Income (Loss), Net of Tax	(83)
Ending balance (in shares) at Jun. 30, 2018		237,643,781
Ending balance at Jun. 30, 2018	3,443,573	$ 2,376	4,609,522	2,213,533	(281)	(3,545,818)	3,279,332	164,241
Beginning balance (in shares) at Mar. 31, 2018		237,628,781
Beginning balance at Mar. 31, 2018	3,416,117	$ 2,376	4,609,274	2,089,946	(291)	(3,453,142)	3,248,163	167,954
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net (loss) income	124,988			123,587			123,587	1,401
Other Comprehensive Income (Loss), Net of Tax	10				10		10
Distributions	(92,676)					(92,676)	(92,676)
Share grants (in shares)		15,000
Share grants	248		248				248
Distributions to noncontrolling interest	(5,114)							(5,114)
Ending balance (in shares) at Jun. 30, 2018		237,643,781
Ending balance at Jun. 30, 2018	$ 3,443,573	$ 2,376	4,609,522	2,213,533	(281)	(3,545,818)	3,279,332	164,241
Beginning balance (in shares) at Dec. 31, 2018	237,729,900	237,729,900
Beginning balance at Dec. 31, 2018	$ 3,179,870	$ 2,377	4,611,419	2,140,796	(266)	(3,731,214)	3,023,112	156,758
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net (loss) income	31,504			30,082			30,082	1,422
Other Comprehensive Income (Loss), Net of Tax	66				66		66
Distributions	(92,714)					(92,714)	(92,714)
Share grants	215		215				215
Distributions to noncontrolling interest	(5,503)							(5,503)
Ending balance (in shares) at Mar. 31, 2019		237,729,900
Ending balance at Mar. 31, 2019	$ 3,113,438	$ 2,377	4,611,634	2,170,878	(200)	(3,823,928)	2,960,761	152,677
Beginning balance (in shares) at Dec. 31, 2018	237,729,900	237,729,900
Beginning balance at Dec. 31, 2018	$ 3,179,870	$ 2,377	4,611,419	2,140,796	(266)	(3,731,214)	3,023,112	156,758
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net (loss) income	(4,312)
Other Comprehensive Income (Loss), Net of Tax	$ 137
Ending balance (in shares) at Jun. 30, 2019	237,740,761	237,740,761
Ending balance at Jun. 30, 2019	$ 3,036,709	$ 2,377	4,611,993	2,133,649	(129)	(3,859,587)	2,888,303	148,406
Beginning balance (in shares) at Mar. 31, 2019		237,729,900
Beginning balance at Mar. 31, 2019	3,113,438	$ 2,377	4,611,634	2,170,878	(200)	(3,823,928)	2,960,761	152,677
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net (loss) income	(35,816)			(37,229)			(37,229)	1,413
Other Comprehensive Income (Loss), Net of Tax	71				71		71
Distributions	(35,659)					(35,659)	(35,659)
Share grants (in shares)		15,000
Share grants	395		395				395
Share repurchases (in shares)		(4,139)
Share repurchases	(36)		(36)				(36)
Distributions to noncontrolling interest	$ (5,684)							(5,684)
Ending balance (in shares) at Jun. 30, 2019	237,740,761	237,740,761
Ending balance at Jun. 30, 2019	$ 3,036,709	$ 2,377	$ 4,611,993	$ 2,133,649	$ (129)	$ (3,859,587)	$ 2,888,303	$ 148,406