Consolidated Statements of Changes in Shareholders' Equity - USD ($) $ in Thousands	Total	Common Stock	Capital Surplus	Retained Earnings	Accumulated Other Comprehensive Income (Loss)	Treasury Stock
Beginning Balance at Dec. 31, 2020	$ 3,016,948	$ 55,057	$ 1,090,450	$ 1,891,246	$ 318,340	$ (338,145)
Total comprehensive income (loss)	(56,500)			92,643	(149,143)
Dividends	(15,571)			(15,571)
Purchase of treasury stock	(4,027)					(4,027)
Issuances of equity awards, net of forfeitures	695		(4,043)			4,738
Recognition of equity-based compensation	4,457		4,457
Sale of treasury stock	151		65			86
Exercise of stock options	12,086		2,738			9,348
Ending Balance at Mar. 31, 2021	2,958,239	55,057	1,093,667	1,968,318	169,197	(328,000)
Beginning Balance at Dec. 31, 2021	3,145,424	55,057	1,110,520	2,176,998	126,314	(323,465)
Total comprehensive income (loss)	(363,479)			105,963	(469,442)
Dividends	(17,832)			(17,832)
Purchase of treasury stock	(22,487)					(22,487)
Issuances of equity awards, net of forfeitures	679		(6,630)			7,309
Recognition of equity-based compensation	5,485		5,485
Sale of treasury stock	138		84			54
Exercise of stock options	477		126			351
Ending Balance at Mar. 31, 2022	$ 2,748,405	$ 55,057	$ 1,109,585	$ 2,265,129	$ (343,128)	$ (338,238)