CONSOLIDATED STATEMENTS OF CHANGES IN EQUITY - USD ($) $ in Thousands	Total	Series B Preferred Stock	Preferred Stock	Common Stock	Treasury Stock	Additional Paid-In Capital	Accumulated Other Comprehensive Income (Loss)	Retained Earnings	Retained Earnings Series B Preferred Stock
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	158,189							158,189
Other comprehensive loss, net of tax	(8,446)						(8,446)
Total comprehensive income	149,743
Cash dividends:
Common Stock	$ (13,020)							(13,020)
Preferred Stock		$ (4,468)							$ (4,468)
Issuance of common shares (in shares)	3,470,664			3,470,664
Issuance of common shares	$ 2,851			$ 694		2,157
Stock-based compensation expense	$ 13,891					13,891
Common stock repurchased (in shares)	(5,435,476)			(5,435,476)	5,435,476
Common stock repurchased	$ (60,000)				$ (60,000)
Shares repurchased related to employee stock-based compensation plans (in shares)	(1,289,391)			(1,289,391)	1,289,391
Shares repurchased related to employee stock-based compensation plans	$ (14,119)				$ (14,119)
Ending Balance (in shares) at Mar. 31, 2019			4,000,000	432,427,285	(20,899,600)
Ending Balance, issued (in shares) at Mar. 31, 2019				453,326,885
Ending Balance at Mar. 31, 2019	3,047,534		$ 400,000	$ 90,666	$ (216,710)	1,290,683	2,177	1,480,718
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		$ 400,000	$ 90,720	$ (324,659)	1,307,630	(12,367)	1,850,512
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	362,173							362,173
Other comprehensive loss, net of tax	(30,907)						(30,907)
Total comprehensive income	331,266
Cash dividends:
Common Stock	(12,595)							(12,595)
Preferred Stock		$ (3,464)							$ (3,464)
Dividend equivalent units related to employee stock-based compensation plans	$ 0					265		265
Issuance of common shares (in shares)	2,837,562			2,837,562
Issuance of common shares	$ 2,872			$ 568		2,304
Stock-based compensation expense	$ 13,610					13,610
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)	(1,105,119)			(1,105,119)	1,105,119
Shares repurchased related to employee stock-based compensation plans	$ (12,136)				$ (12,136)
Ending Balance (in shares) at Mar. 31, 2020			4,000,000	375,088,960	(81,348,528)
Ending Balance, issued (in shares) at Mar. 31, 2020				456,437,488
Ending Balance at Mar. 31, 2020	$ 2,120,583		$ 400,000	$ 91,288	$ (798,039)	$ 1,226,886	$ (43,274)	$ 1,243,722