CONSOLIDATED STATEMENTS OF CHANGES IN EQUITY - USD ($) $ in Thousands	Total	Series B Preferred Stock	Cumulative Effect, Period Of Adoption, Adjustment	Cumulative Effect, Period Of Adoption, Adjusted Balance	Preferred Stock Shares	Preferred Stock Shares Cumulative Effect, Period Of Adoption, Adjusted Balance	Common Stock	Common Stock Cumulative Effect, Period Of Adoption, Adjusted Balance	Treasury Stock	Treasury Stock Cumulative Effect, Period Of Adoption, Adjusted Balance	Additional Paid-In Capital	Additional Paid-In Capital Cumulative Effect, Period Of Adoption, Adjusted Balance	Accumulated Other Comprehensive Loss	Accumulated Other Comprehensive Loss Cumulative Effect, Period Of Adoption, Adjusted Balance	Retained Earnings	Retained Earnings Series B Preferred Stock	Retained Earnings Cumulative Effect, Period Of Adoption, Adjustment	Retained Earnings Cumulative Effect, Period Of Adoption, Adjusted Balance
Beginning Balance, issued (in shares) at Dec. 31, 2019					4,000,000	4,000,000	453,599,926	453,599,926
Beginning Balance (in shares) at Dec. 31, 2019							421,093,364	421,093,364	(32,506,562)	(32,506,562)
Beginning Balance at Dec. 31, 2019	$ 3,311,836		$ (952,639)	$ 2,359,197	$ 400,000	$ 400,000	$ 90,720	$ 90,720	$ (324,659)	$ (324,659)	$ 1,307,630	$ 1,307,630	$ (12,367)	$ (12,367)	$ 1,850,512		$ (952,639)	$ 897,873
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	276,962														276,962
Other comprehensive loss, net of tax	(31,704)												(31,704)
Total comprehensive income (loss)	245,258
Dividends, Cash [Abstract]
Common Stock	(35,344)														(35,344)
Preferred Stock		$ (5,942)														$ (5,942)
Dividend equivalent units related to employee stock-based compensation plans	$ (10)										270				(280)
Issuance of common shares (in shares)	2,985,297						2,985,297
Issuance of common shares	$ 2,881						$ 597				2,284
Stock-based compensation expense	$ 21,189										21,189
Common stock repurchased (in shares)	(47,736,847)						(47,736,847)		(47,736,847)
Common stock repurchased	$ (558,167)								$ (461,244)		(96,923)
Shares repurchased related to employee stock-based compensation plans (in shares)	(1,106,027)						(1,106,027)		(1,106,027)
Shares repurchased related to employee stock-based compensation plans	$ (12,143)								$ (12,143)
Ending Balance, issued (in shares) at Jun. 30, 2020					4,000,000		456,585,223
Ending Balance (in shares) at Jun. 30, 2020							375,235,787		(81,349,436)
Ending Balance at Jun. 30, 2020	2,016,919				$ 400,000		$ 91,317		$ (798,046)		1,234,450		(44,071)		1,133,269
Beginning Balance, issued (in shares) at Mar. 31, 2020					4,000,000		456,437,488
Beginning Balance (in shares) at Mar. 31, 2020							375,088,960		(81,348,528)
Beginning Balance at Mar. 31, 2020	2,120,583				$ 400,000		$ 91,288		$ (798,039)		1,226,886		(43,274)		1,243,722
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	(85,211)														(85,211)
Other comprehensive loss, net of tax	(797)												(797)
Total comprehensive income (loss)	(86,008)
Dividends, Cash [Abstract]
Common Stock	(22,749)														(22,749)
Preferred Stock		(2,478)														(2,478)
Dividend equivalent units related to employee stock-based compensation plans	$ 0										15				(15)
Issuance of common shares (in shares)	147,735						147,735
Issuance of common shares	$ (1)						$ 29				(30)
Stock-based compensation expense	$ 7,579										7,579
Common stock repurchased (in shares)	0
Shares repurchased related to employee stock-based compensation plans (in shares)	(908)						(908)		(908)
Shares repurchased related to employee stock-based compensation plans	$ (7)								$ (7)
Ending Balance, issued (in shares) at Jun. 30, 2020					4,000,000		456,585,223
Ending Balance (in shares) at Jun. 30, 2020							375,235,787		(81,349,436)
Ending Balance at Jun. 30, 2020	2,016,919				$ 400,000		$ 91,317		$ (798,046)		1,234,450		(44,071)		1,133,269
Beginning Balance, issued (in shares) at Dec. 31, 2020					2,510,696		456,729,251
Beginning Balance (in shares) at Dec. 31, 2020					2,510,696		375,287,999		(81,441,252)
Beginning Balance at Dec. 31, 2020	2,562,835				$ 251,070		$ 91,346		$ (798,993)		1,331,247		(34,200)		1,722,365
Ending Balance, issued (in shares) at Mar. 31, 2021					2,510,696		431,053,178
Ending Balance (in shares) at Mar. 31, 2021							328,351,576		(102,701,602)
Ending Balance at Mar. 31, 2021	2,608,464				$ 251,070		$ 86,211		$ (1,108,630)		1,052,904		(24,077)		2,350,986
Beginning Balance, issued (in shares) at Dec. 31, 2020					2,510,696		456,729,251
Beginning Balance (in shares) at Dec. 31, 2020					2,510,696		375,287,999		(81,441,252)
Beginning Balance at Dec. 31, 2020	2,562,835				$ 251,070		$ 91,346		$ (798,993)		1,331,247		(34,200)		1,722,365
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	781,408														781,408
Other comprehensive loss, net of tax	12,560												12,560
Total comprehensive income (loss)	793,968
Dividends, Cash [Abstract]
Common Stock	(20,170)														(20,170)
Preferred Stock		(2,393)														(2,393)
Dividend equivalent units related to employee stock-based compensation plans	$ (16)										522				(538)
Issuance of common shares (in shares)	3,281,307						3,281,307
Issuance of common shares	$ 2,021						$ 656				1,365
Stock-based compensation expense	17,568										17,568
Common stock repurchased and cancelled (in shares)							(28,502,460)
Fees related to first-quarter 2021 common stock tender offer	$ (472,388)						$ (5,700)				(466,688)
Common stock repurchased (in shares)	(71,509,671)						(43,007,211)		(43,007,211)
Common stock repurchased	$ (560,117)								$ (734,801)		174,684
Shares repurchased related to employee stock-based compensation plans (in shares)	(1,252,412)						(1,252,412)		(1,252,412)
Shares repurchased related to employee stock-based compensation plans	$ (17,930)								$ (17,930)
Ending Balance, issued (in shares) at Jun. 30, 2021					2,510,696		431,508,098
Ending Balance (in shares) at Jun. 30, 2021					2,510,696		305,807,223		(125,700,875)
Ending Balance at Jun. 30, 2021	2,303,378				$ 251,070		$ 86,302		$ (1,551,724)		1,058,698		(21,640)		2,480,672
Beginning Balance, issued (in shares) at Mar. 31, 2021					2,510,696		431,053,178
Beginning Balance (in shares) at Mar. 31, 2021							328,351,576		(102,701,602)
Beginning Balance at Mar. 31, 2021	2,608,464				$ 251,070		$ 86,211		$ (1,108,630)		1,052,904		(24,077)		2,350,986
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	140,201														140,201
Other comprehensive loss, net of tax	2,437												2,437
Total comprehensive income (loss)	142,638
Dividends, Cash [Abstract]
Common Stock	(9,264)														(9,264)
Preferred Stock		$ (1,192)														$ (1,192)
Dividend equivalent units related to employee stock-based compensation plans	$ 0										59				(59)
Issuance of common shares (in shares)	454,920						454,920
Issuance of common shares	$ (40)						$ 91				(131)
Stock-based compensation expense	6,444										6,444
Fees related to first-quarter 2021 common stock tender offer	$ (578)										(578)
Common stock repurchased (in shares)	(22,806,841)						(22,806,841)		(22,806,841)
Common stock repurchased	$ (439,477)								$ (439,477)
Shares repurchased related to employee stock-based compensation plans (in shares)	(192,432)						(192,432)		(192,432)
Shares repurchased related to employee stock-based compensation plans	$ (3,617)								$ (3,617)
Ending Balance, issued (in shares) at Jun. 30, 2021					2,510,696		431,508,098
Ending Balance (in shares) at Jun. 30, 2021					2,510,696		305,807,223		(125,700,875)
Ending Balance at Jun. 30, 2021	$ 2,303,378				$ 251,070		$ 86,302		$ (1,551,724)		$ 1,058,698		$ (21,640)		$ 2,480,672