Condensed Consolidated Statements of Shareholders' Deficit (unaudited) - USD ($) $ in Thousands	Total	Cumulative Effect Adjustment for Adoption of New Accounting Standard	Common Stock	Additional Paid-in Capital	Additional Paid-in Capital Cumulative Effect Adjustment for Adoption of New Accounting Standard	Accumulated Other Comprehensive (Loss) Income	Distributions in Excess of Accumulated Earnings	Distributions in Excess of Accumulated Earnings Cumulative Effect Adjustment for Adoption of New Accounting Standard	Noncontrolling Interest - OP Units	Noncontrolling Interest - Non-voting Preferred Shares
Beginning balance, value at Dec. 31, 2019	$ (1,483,164)		$ 19	$ 951,295		$ (23,442)	$ (2,494,740)		$ 83,704
Beginning balance, shares at Dec. 31, 2019			192,141,634
Net income (loss)	(678,595)						(666,597)		(11,998)
Other comprehensive income (loss)	(2,540)					(2,495)			(45)
Common stock dividends declared	(58,286)						(58,286)
Distributions to noncontrolling interest	(1,039)								(1,039)
Cumulative non-voting convertible preferred stock	125									$ 125
Payments related to tax withholding for stock-based compensation	(1,050)			(1,050)
Stock-based compensation	7,105			7,105
Stock-based compensation, shares			337,600
Issuance of common stock - employee stock purchase plan	306			306
Issuance of common stock - employee stock purchase plan, in shares			43,849
Ending balance, value at Jun. 30, 2020	(2,217,138)		$ 19	957,656		(25,937)	(3,219,623)		70,622	125
Ending balance, shares at Jun. 30, 2020			192,523,083
Beginning balance, value at Mar. 31, 2020	(1,595,451)		$ 19	954,223		(28,717)	(2,602,777)		81,676	125
Beginning balance, shares at Mar. 31, 2020			192,281,092
Net income (loss)	(598,329)						(587,744)		(10,585)
Other comprehensive income (loss)	2,830					2,780			50
Common stock dividends declared	(29,102)						(29,102)
Distributions to noncontrolling interest	(519)								(519)
Payments related to tax withholding for stock-based compensation	(677)			(677)
Stock-based compensation	4,110			4,110
Stock-based compensation, shares			241,991
Ending balance, value at Jun. 30, 2020	(2,217,138)		$ 19	957,656		(25,937)	(3,219,623)		70,622	125
Ending balance, shares at Jun. 30, 2020			192,523,083
Beginning balance, value at Dec. 31, 2020	$ (2,072,376)	$ (45,310)	$ 23	1,209,141	$ (59,908)	(20,367)	(3,330,455)	$ 14,598	69,157	125
Beginning balance, shares at Dec. 31, 2020			231,261,958
Accounting Standards Update Extensible List	unit:AccountingStandardUpdate202006Member
Net income (loss)	$ 45,137						44,469		668
Other comprehensive income (loss)	5,658					5,575			83
Common stock dividends declared	(69,983)						(69,983)
Distributions to noncontrolling interest	(1,040)								(1,040)
Payments related to tax withholding for stock-based compensation	(2,642)			(2,642)
Stock-based compensation	6,797			6,797
Stock-based compensation, shares			507,199
Issuance of common stock - employee stock purchase plan	319			319
Issuance of common stock - employee stock purchase plan, in shares			35,764
Ending balance, value at Jun. 30, 2021	(2,133,440)		$ 23	1,153,707		(14,792)	(3,341,371)		68,868	125
Ending balance, shares at Jun. 30, 2021			231,804,921
Beginning balance, value at Mar. 31, 2021	(2,153,690)		$ 23	1,150,550		(17,580)	(3,355,423)		68,615	125
Beginning balance, shares at Mar. 31, 2021			231,694,203
Net income (loss)	49,639						48,907		732
Other comprehensive income (loss)	2,829					2,788			41
Common stock dividends declared	(34,855)						(34,855)
Distributions to noncontrolling interest	(520)								(520)
Payments related to tax withholding for stock-based compensation	(336)			(336)
Stock-based compensation	3,462			3,462
Stock-based compensation, shares			110,718
Issuance of common stock - employee stock purchase plan	31			31
Ending balance, value at Jun. 30, 2021	$ (2,133,440)		$ 23	$ 1,153,707		$ (14,792)	$ (3,341,371)		$ 68,868	$ 125
Ending balance, shares at Jun. 30, 2021			231,804,921