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	452,974				452,804				170
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)			518,292
Share-based compensation	7,648		$ 5	6,978					665
Distributions	(3,852)					142	(3,994)
Adjustment for noncontrolling interest				582					(582)
Balance as of end of period (in shares) at Jun. 30, 2019		4,915,196	121,922,120
Balance as of end 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
Balance as of beginning of period (in shares) at Mar. 31, 2019		4,915,196	121,899,625
Balance as of beginning of period at Mar. 31, 2019	3,391,561	$ 119,263	$ 1,219	4,304,560	3,081,492	(3,420,512)	(695,733)	0	1,272
Increase (Decrease) in Stockholders' Equity
Net income	242,377				242,286				91
Unrealized gain on marketable securities	0
Surrender of shares for tax withholding (in shares)			(4,414)
Surrender of shares for tax withholding	(145)			(145)
Share-based compensation (in shares)			26,909
Share-based compensation	3,721			3,393					328
Distributions	(1,891)					106	(1,997)
Adjustment for noncontrolling interest				241					(241)
Balance as of end of period (in shares) at Jun. 30, 2019		4,915,196	121,922,120
Balance as of end 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
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	453,393				452,591				802
Unrealized gain on marketable securities	0
Repurchase of shares (in shares)			(711,000)
Repurchase of shares	(20,869)		$ (7)	(20,862)
Surrender of shares for tax withholding (in shares)			(183,466)
Surrender of shares for tax withholding	(6,012)		$ (2)	(6,010)
Share-based compensation (in shares)			491,891
Share-based compensation	6,571		$ 5	5,859					707
Contributions	1								1
Distributions	(5,184)					(1,190)	(3,994)
Redemption of noncontrolling interest	(31)								(31)
Adjustment for noncontrolling interest				(4,573)					4,573
Balance as of end of period (in shares) at Jun. 30, 2020		4,915,196	121,521,624
Balance as of end 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
Balance as of beginning of period (in shares) at Mar. 31, 2020		4,915,196	121,502,520
Balance as of beginning of period at Mar. 31, 2020	3,644,614	$ 119,263	$ 1,215	4,285,266	3,788,413	(3,852,856)	(703,721)		7,034
Increase (Decrease) in Stockholders' Equity
Net income	27,886				27,832				54
Unrealized gain on marketable securities	0
Share-based compensation (in shares)			19,104
Share-based compensation	3,268			2,906					362
Contributions	1								1
Distributions	(1,997)					0	(1,997)
Redemption of noncontrolling interest	(31)								(31)
Adjustment for noncontrolling interest				73					(73)
Balance as of end of period (in shares) at Jun. 30, 2020		4,915,196	121,521,624
Balance as of end 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