CONSOLIDATED STATEMENTS OF CHANGES IN EQUITY - USD ($) $ in Thousands	Total	Series B Preferred Stock	Cumulative Effect, Period Of Adoption, Adjustment	Preferred Stock	Common Stock	Treasury Stock	Additional Paid-In Capital	Accumulated Other Comprehensive Income (Loss)	Retained Earnings	Retained Earnings Series B Preferred Stock	Retained Earnings Cumulative Effect, Period Of Adoption, Adjustment
Beginning Balance (in shares) at Dec. 31, 2018				4,000,000	435,681,488	(14,174,733)
Beginning Balance, issued (in shares) at Dec. 31, 2018					449,856,221
Beginning Balance at Dec. 31, 2018	$ 2,972,656			$ 400,000	$ 89,972	$ (142,591)	$ 1,274,635	$ 10,623	$ 1,340,017
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	308,466								308,466
Other comprehensive loss, net of tax	(24,202)							(24,202)
Total comprehensive income	284,264
Cash dividends declared:
Common Stock	(38,824)								(38,824)
Preferred Stock		$ (8,799)								$ (8,799)
Dividend equivalent units related to employee stock-based compensation plans	$ 0						5		(5)
Issuance of common shares (in shares)	3,651,684				3,651,684
Issuance of common shares	$ 3,026				$ 730		2,296
Stock-based compensation expense	$ 19,473						19,473
Common stock repurchased (in shares)	(11,424,755)				(11,424,755)	(11,424,755)
Common stock repurchased	$ (120,120)					$ (120,120)
Shares repurchased related to employee stock-based compensation plans (in shares)	(1,313,427)				(1,313,427)	(1,313,427)
Shares repurchased related to employee stock-based compensation plans	$ (14,360)					$ (14,360)
Ending Balance (in shares) at Jun. 30, 2019				4,000,000	426,594,990	(26,912,915)
Ending Balance, issued (in shares) at Jun. 30, 2019					453,507,905
Ending Balance at Jun. 30, 2019	3,097,316			$ 400,000	$ 90,702	$ (277,071)	1,296,409	(13,579)	1,600,855
Beginning Balance (in shares) at Mar. 31, 2019				4,000,000	432,427,285	(20,899,600)
Beginning Balance, issued (in shares) at Mar. 31, 2019					453,326,885
Beginning Balance at Mar. 31, 2019	3,047,534			$ 400,000	$ 90,666	$ (216,710)	1,290,683	2,177	1,480,718
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	150,277								150,277
Other comprehensive loss, net of tax	(15,756)							(15,756)
Total comprehensive income	134,521
Cash dividends declared:
Common Stock	(25,804)								(25,804)
Preferred Stock		(4,331)								(4,331)
Dividend equivalent units related to employee stock-based compensation plans	$ 0						5		(5)
Issuance of common shares (in shares)	181,020				181,020
Issuance of common shares	$ 175				$ 36		139
Stock-based compensation expense	$ 5,582						5,582
Common stock repurchased (in shares)	(5,989,279)				(5,989,279)	(5,989,279)
Common stock repurchased	$ (60,120)					$ (60,120)
Shares repurchased related to employee stock-based compensation plans (in shares)	(24,036)				(24,036)	(24,036)
Shares repurchased related to employee stock-based compensation plans	$ (241)					$ (241)
Ending Balance (in shares) at Jun. 30, 2019				4,000,000	426,594,990	(26,912,915)
Ending Balance, issued (in shares) at Jun. 30, 2019					453,507,905
Ending Balance at Jun. 30, 2019	3,097,316			$ 400,000	$ 90,702	$ (277,071)	1,296,409	(13,579)	1,600,855
Beginning Balance (in shares) at Dec. 31, 2019				4,000,000	421,093,364	(32,506,562)
Beginning Balance, issued (in shares) at Dec. 31, 2019					453,599,926
Beginning Balance at Dec. 31, 2019	3,311,836		$ (952,639)	$ 400,000	$ 90,720	$ (324,659)	1,307,630	(12,367)	1,850,512		$ (952,639)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	276,962								276,962
Other comprehensive loss, net of tax	(31,704)							(31,704)
Total comprehensive income	245,258
Cash dividends declared:
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 (in shares) at Jun. 30, 2020				4,000,000	375,235,787	(81,349,436)
Ending Balance, issued (in shares) at Jun. 30, 2020					456,585,223
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 (in shares) at Mar. 31, 2020				4,000,000	375,088,960	(81,348,528)
Beginning Balance, issued (in shares) at Mar. 31, 2020					456,437,488
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 income	(85,211)								(85,211)
Other comprehensive loss, net of tax	(797)							(797)
Total comprehensive income	(86,008)
Cash dividends declared:
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 (in shares) at Jun. 30, 2020				4,000,000	375,235,787	(81,349,436)
Ending Balance, issued (in shares) at Jun. 30, 2020					456,585,223
Ending Balance at Jun. 30, 2020	$ 2,016,919			$ 400,000	$ 91,317	$ (798,046)	$ 1,234,450	$ (44,071)	$ 1,133,269