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	436,924								436,924
Other comprehensive loss, net of tax	(30,806)							(30,806)
Total comprehensive income	406,118
Cash dividends declared:
Common Stock	(38,485)								(38,485)
Preferred Stock		$ (12,952)								$ (12,952)
Dividend equivalent units related to employee stock-based compensation plans	$ 0						5		(5)
Issuance of common shares (in shares)	3,677,821				3,677,821
Issuance of common shares	$ 3,119				$ 735		2,384
Stock-based compensation expense	$ 24,779						24,604		175
Common stock repurchased (in shares)	(15,861,718)				(15,861,718)	(15,861,718)
Common stock repurchased	$ (157,597)					$ (157,597)
Shares repurchased related to employee stock-based compensation plans (in shares)	(1,328,665)				(1,328,665)	(1,328,665)
Shares repurchased related to employee stock-based compensation plans	$ (14,506)					$ (14,506)
Ending Balance (in shares) at Sep. 30, 2019				4,000,000	422,168,926	(31,365,116)
Ending Balance, issued (in shares) at Sep. 30, 2019					453,534,042
Ending Balance at Sep. 30, 2019	3,183,132			$ 400,000	$ 90,707	$ (314,694)	1,301,628	(20,183)	1,725,674
Beginning Balance (in shares) at Jun. 30, 2019				4,000,000	426,594,990	(26,912,915)
Beginning Balance, issued (in shares) at Jun. 30, 2019					453,507,905
Beginning Balance at Jun. 30, 2019	3,097,316			$ 400,000	$ 90,702	$ (277,071)	1,296,409	(13,579)	1,600,855
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	128,458								128,458
Other comprehensive loss, net of tax	(6,604)							(6,604)
Total comprehensive income	121,854
Cash dividends declared:
Preferred Stock		(4,153)								(4,153)
Common stock dividend accrual adjustment	$ 339								339
Issuance of common shares (in shares)	26,137				26,137
Issuance of common shares	$ 92				$ 5		87
Stock-based compensation expense	$ 5,307						5,132		175
Common stock repurchased (in shares)	(4,436,963)				(4,436,963)	(4,436,963)
Common stock repurchased	$ (37,477)					$ (37,477)
Shares repurchased related to employee stock-based compensation plans (in shares)	(15,238)				(15,238)	(15,238)
Shares repurchased related to employee stock-based compensation plans	$ (146)					$ (146)
Ending Balance (in shares) at Sep. 30, 2019				4,000,000	422,168,926	(31,365,116)
Ending Balance, issued (in shares) at Sep. 30, 2019					453,534,042
Ending Balance at Sep. 30, 2019	3,183,132			$ 400,000	$ 90,707	$ (314,694)	1,301,628	(20,183)	1,725,674
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	447,990								447,990
Other comprehensive loss, net of tax	(26,574)							(26,574)
Total comprehensive income	421,416
Cash dividends declared:
Common Stock	(35,097)								(35,097)
Preferred Stock		(8,000)								(8,000)
Dividend equivalent units related to employee stock-based compensation plans	$ (10)						270		(280)
Issuance of common shares (in shares)	2,990,447				2,990,447
Issuance of common shares	$ 2,897				$ 599		2,298
Stock-based compensation expense	$ 30,375						30,207		168
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)	(1,109,149)				(1,109,149)	1,109,149
Shares repurchased related to employee stock-based compensation plans	$ (12,165)					$ (12,165)
Ending Balance (in shares) at Sep. 30, 2020				4,000,000	375,237,815	(81,352,558)
Ending Balance, issued (in shares) at Sep. 30, 2020					456,590,373
Ending Balance at Sep. 30, 2020	2,200,446			$ 400,000	$ 91,319	$ (798,068)	1,243,482	(38,941)	1,302,654
Beginning Balance (in shares) at Jun. 30, 2020				4,000,000	375,235,787	(81,349,436)
Beginning Balance, issued (in shares) at Jun. 30, 2020					456,585,223
Beginning Balance at Jun. 30, 2020	2,016,919			$ 400,000	$ 91,317	$ (798,046)	1,234,450	(44,071)	1,133,269
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	171,028								171,028
Other comprehensive loss, net of tax	5,130							5,130
Total comprehensive income	176,158
Cash dividends declared:
Preferred Stock		$ (2,058)								$ (2,058)
Common stock dividend accrual adjustment	$ (247)								(247)
Issuance of common shares (in shares)	5,150				5,150
Issuance of common shares	$ 16				$ 2		14
Stock-based compensation expense	$ 9,186						9,018		(168)
Common stock repurchased (in shares)	0
Shares repurchased related to employee stock-based compensation plans (in shares)	(3,122)				(3,122)	3,122
Shares repurchased related to employee stock-based compensation plans	$ (22)					$ (22)
Ending Balance (in shares) at Sep. 30, 2020				4,000,000	375,237,815	(81,352,558)
Ending Balance, issued (in shares) at Sep. 30, 2020					456,590,373
Ending Balance at Sep. 30, 2020	$ 2,200,446			$ 400,000	$ 91,319	$ (798,068)	$ 1,243,482	$ (38,941)	$ 1,302,654