Condensed Consolidated Statements of Shareholders' Equity - USD ($) $ in Thousands	Total	Preferred Stock	Common Stock	Additional Paid-In Capital	Accumulated Other Comprehensive Income (Loss)	Retained Earnings	Treasury Stock
Beginning balance at Dec. 31, 2020	$ 8,771,092	$ 0	$ 113,218	$ 527,435	$ 3,029,244	$ 5,874,109	$ (772,914)
Increase (Decrease) in Stockholders' Equity
Comprehensive income (loss)	(826,212)				(1,004,729)	178,517
Common dividends declared	(20,435)					(20,435)
Acquisition of treasury stock	(132,720)						(132,720)
Stock-based compensation	7,888			(11,422)		1,168	18,142
Exercise of stock options	32,724					(12,807)	45,531
Ending balance at Mar. 31, 2021	7,832,337	0	113,218	516,013	2,024,515	6,020,552	(841,961)
Beginning balance at Dec. 31, 2020	8,771,092	0	113,218	527,435	3,029,244	5,874,109	(772,914)
Increase (Decrease) in Stockholders' Equity
Comprehensive income (loss)	99,170
Ending balance at Jun. 30, 2021	8,616,922	0	113,218	524,647	2,750,279	6,185,966	(957,188)
Beginning balance at Mar. 31, 2021	7,832,337	0	113,218	516,013	2,024,515	6,020,552	(841,961)
Increase (Decrease) in Stockholders' Equity
Comprehensive income (loss)	925,382				725,764	199,618
Common dividends declared	(20,171)					(20,171)
Acquisition of treasury stock	(162,864)						(162,864)
Stock-based compensation	8,634			8,634
Exercise of stock options	33,604					(14,033)	47,637
Ending balance at Jun. 30, 2021	8,616,922	0	113,218	524,647	2,750,279	6,185,966	(957,188)
Beginning balance at Dec. 31, 2021	8,642,806	0	109,218	520,564	2,677,583	6,182,100	(846,659)
Increase (Decrease) in Stockholders' Equity
Comprehensive income (loss)	(1,643,727)				(1,808,088)	164,361
Common dividends declared	(20,543)					(20,543)
Acquisition of treasury stock	(119,482)						(119,482)
Stock-based compensation	9,035			2,504		(345)	6,876
Exercise of stock options	25,931					(9,964)	35,895
Ending balance at Mar. 31, 2022	6,894,020	0	109,218	523,068	869,495	6,315,609	(923,370)
Beginning balance at Dec. 31, 2021	8,642,806	0	109,218	520,564	2,677,583	6,182,100	(846,659)
Increase (Decrease) in Stockholders' Equity
Comprehensive income (loss)	(3,067,711)
Ending balance at Jun. 30, 2022	5,323,110	0	109,218	531,516	(731,493)	6,469,956	(1,056,087)
Beginning balance at Mar. 31, 2022	6,894,020	0	109,218	523,068	869,495	6,315,609	(923,370)
Increase (Decrease) in Stockholders' Equity
Comprehensive income (loss)	(1,423,984)				(1,600,988)	177,004
Common dividends declared	(20,238)					(20,238)
Acquisition of treasury stock	(143,939)						(143,939)
Stock-based compensation	8,448			8,448
Exercise of stock options	8,803					(2,419)	11,222
Ending balance at Jun. 30, 2022	$ 5,323,110	$ 0	$ 109,218	$ 531,516	$ (731,493)	$ 6,469,956	$ (1,056,087)