CONDENSED CONSOLIDATED STATEMENTS OF EQUITY - USD ($) $ in Thousands	Total	Series D Preferred Shares	Common Shares	Additional Paid in Capital	Cumulative Net Income	Cumulative Common Distributions	Cumulative Preferred Distributions	Cumulative Other Comprehensive Loss	Noncontrolling Interest
Balance as of beginning of period (in shares) at Dec. 31, 2018		4,915,196	121,572,155
Balance as of beginning of period at Dec. 31, 2018	$ 3,183,998	$ 119,263	$ 1,216	$ 4,305,974	$ 2,870,974	$ (3,420,548)	$ (693,736)	$ (342)	$ 1,197
Increase (Decrease) in Stockholders' Equity
Net income	476,870				476,690				180
Unrealized gain on marketable securities	342							342
Surrender of shares for tax withholding (in shares)			(168,327)
Surrender of shares for tax withholding	(5,487)		$ (2)	(5,485)
Share-based compensation (in shares)			520,371
Share-based compensation	11,056		$ 5	10,056					995
Distributions	(438,666)					(431,399)	(5,991)		(1,276)
Adjustment for noncontrolling interest				(192)					192
Balance as of end of period (in shares) at Sep. 30, 2019		4,915,196	121,924,199
Balance as of end of period at Sep. 30, 2019	3,228,113	$ 119,263	$ 1,219	4,310,353	3,347,664	(3,851,947)	(699,727)	0	1,288
Balance as of beginning of period (in shares) at Jun. 30, 2019		4,915,196	121,922,120
Balance as of beginning of period at Jun. 30, 2019	3,635,623	$ 119,263	$ 1,219	4,308,049	3,323,778	(3,420,406)	(697,730)	0	1,450
Increase (Decrease) in Stockholders' Equity
Net income	23,896				23,886				10
Unrealized gain on marketable securities	0
Share-based compensation (in shares)			2,079
Share-based compensation	3,408			3,078					330
Distributions	(434,814)					(431,541)	(1,997)		(1,276)
Adjustment for noncontrolling interest				(774)					774
Balance as of end of period (in shares) at Sep. 30, 2019		4,915,196	121,924,199
Balance as of end of period at Sep. 30, 2019	3,228,113	$ 119,263	$ 1,219	4,310,353	3,347,664	(3,851,947)	(699,727)	$ 0	1,288
Balance as of beginning of period (in shares) at Dec. 31, 2019		4,915,196	121,924,199
Balance as of beginning of period at Dec. 31, 2019	3,245,872	$ 119,263	$ 1,219	4,313,831	3,363,654	(3,851,666)	(701,724)		1,295
Increase (Decrease) in Stockholders' Equity
Net income	453,763				452,960				803
Repurchase of shares (in shares)			(711,000)
Repurchase of shares	(20,869)		$ (7)	(20,862)
Unrealized gain on marketable securities	0
Surrender of shares for tax withholding (in shares)			(183,992)
Surrender of shares for tax withholding	(6,026)		$ (2)	(6,024)
Share-based compensation (in shares)			495,303
Share-based compensation	9,891		$ 5	8,767					1,119
Contributions	1								1
Distributions	(439,495)					(432,384)	(5,991)		(1,120)
Redemption of noncontrolling interest	(31)								(31)
Adjustment for noncontrolling interest				(4,419)					4,419
Balance as of end of period (in shares) at Sep. 30, 2020		4,915,196	121,524,510
Balance as of end of period at Sep. 30, 2020	3,243,106	$ 119,263	$ 1,215	4,291,293	3,816,614	(4,284,050)	(707,715)		6,486
Balance as of beginning of period (in shares) at Jun. 30, 2020		4,915,196	121,521,624
Balance as of beginning of period at Jun. 30, 2020	3,673,741	$ 119,263	$ 1,215	4,288,245	3,816,245	(3,852,856)	(705,718)		7,347
Increase (Decrease) in Stockholders' Equity
Net income	370				369				1
Unrealized gain on marketable securities	0
Surrender of shares for tax withholding (in shares)			(526)
Surrender of shares for tax withholding	(14)			(14)
Share-based compensation (in shares)			3,412
Share-based compensation	3,320			2,908					412
Distributions	(434,311)					(431,194)	(1,997)		(1,120)
Adjustment for noncontrolling interest				154					(154)
Balance as of end of period (in shares) at Sep. 30, 2020		4,915,196	121,524,510
Balance as of end of period at Sep. 30, 2020	$ 3,243,106	$ 119,263	$ 1,215	$ 4,291,293	$ 3,816,614	$ (4,284,050)	$ (707,715)		$ 6,486