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)	120,489			274,522	(154,033)
Dividends	(49,200)			(49,200)
Purchase of treasury stock	(4,269)					(4,269)
Issuances of equity awards, net of forfeitures	695		(4,374)			5,069
Recognition of equity-based compensation	13,401		13,401
Sale of treasury stock	437		223			214
Exercise of stock options	14,339		3,118			11,221
Ending Balance at Sep. 30, 2021	3,112,840	55,057	1,102,818	2,116,568	164,307	(325,910)
Beginning Balance at Jun. 30, 2021	3,090,244	55,057	1,098,139	2,040,134	223,107	(326,193)
Total comprehensive income (loss)	35,667			94,467	(58,800)
Dividends	(18,033)			(18,033)
Purchase of treasury stock	(181)					(181)
Issuances of equity awards, net of forfeitures			(252)			252
Recognition of equity-based compensation	4,791		4,791
Sale of treasury stock	136		75			61
Exercise of stock options	216		65			151
Ending Balance at Sep. 30, 2021	3,112,840	55,057	1,102,818	2,116,568	164,307	(325,910)
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)	(554,065)			331,509	(885,574)
Dividends	(54,085)			(54,085)
Purchase of treasury stock	(31,806)					(31,806)
Issuances of equity awards, net of forfeitures	679		(6,630)			7,309
Recognition of equity-based compensation	16,062		16,062
Sale of treasury stock	429		257			172
Exercise of stock options	907		280			627
Ending Balance at Sep. 30, 2022	2,523,545	55,057	1,120,489	2,454,422	(759,260)	(347,163)
Beginning Balance at Jun. 30, 2022	2,642,888	55,057	1,115,504	2,384,454	(564,803)	(347,324)
Total comprehensive income (loss)	(106,467)			87,990	(194,457)
Dividends	(18,022)			(18,022)
Recognition of equity-based compensation	4,839		4,839
Sale of treasury stock	144		83			61
Exercise of stock options	163		63			100
Ending Balance at Sep. 30, 2022	$ 2,523,545	$ 55,057	$ 1,120,489	$ 2,454,422	$ (759,260)	$ (347,163)