Consolidated Statements of Shareholders' Equity - USD ($) shares in Thousands, $ in Thousands	Common Stock [Member]	AOCI Attributable to Parent [Member]	Accumulated Distributions in Excess of Net Income [Member]	Total
Balance at Dec. 31, 2017	$ 4,588,188	$ 9,778	$ (1,026,881)	$ 3,571,085
Balance (in Shares) at Dec. 31, 2017	229,962
Share based compensation, net	$ 6,139			6,139
Share based compensation, net (in Shares)	397
Common shares repurchased	$ (4,304)			(4,304)
Common shares repurchased (in Shares)	(255)
Issuance of common shares, net	$ 4,677			4,677
Issuance of common shares, net (in Shares)	243
Interest rate derivatives		8,032		8,032
Net income			109,812	109,812
Distributions declared to shareholders			(138,204)	(138,204)
Balance at Jun. 30, 2018	$ 4,594,700	17,810	(1,055,273)	3,557,237
Balance (in Shares) at Jun. 30, 2018	230,347
Balance at Mar. 31, 2018	$ 4,594,247	16,070	(1,053,843)	3,556,474
Balance (in Shares) at Mar. 31, 2018	230,340
Share based compensation, net	$ 455			455
Share based compensation, net (in Shares)	7
Issuance of common shares, net	$ (2)			(2)
Interest rate derivatives		1,740		1,740
Net income			67,630	67,630
Distributions declared to shareholders			(69,060)	(69,060)
Balance at Jun. 30, 2018	$ 4,594,700	17,810	(1,055,273)	3,557,237
Balance (in Shares) at Jun. 30, 2018	230,347
Balance at Dec. 31, 2018	$ 4,495,073	10,006	(1,096,069)	3,409,010
Balance (in Shares) at Dec. 31, 2018	223,997
Cumulative effect of the adoption of ASU 2016-02 related to leases			(5,201)	(5,201)
Share based compensation, net	$ 2,621			2,621
Share based compensation, net (in Shares)	146
Common shares repurchased	$ (4,096)			(4,096)
Common shares repurchased (in Shares)	(274)
Interest rate derivatives		(16,164)		(16,164)
Net income			100,241	100,241
Distributions declared to shareholders			(134,343)	(134,343)
Balance at Jun. 30, 2019	$ 4,493,598	(6,158)	(1,135,372)	3,352,068
Balance (in Shares) at Jun. 30, 2019	223,869
Balance at Mar. 31, 2019	$ 4,493,362	3,962	(1,130,297)	3,367,027
Balance (in Shares) at Mar. 31, 2019	223,868
Share based compensation, net	$ 236			236
Share based compensation, net (in Shares)	1
Interest rate derivatives		(10,120)		(10,120)
Net income			62,090	62,090
Distributions declared to shareholders			(67,165)	(67,165)
Balance at Jun. 30, 2019	$ 4,493,598	$ (6,158)	$ (1,135,372)	$ 3,352,068
Balance (in Shares) at Jun. 30, 2019	223,869