Condensed Consolidated Statements of Stockholders' Equity (Unaudited) - USD ($) $ in Thousands	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Treasury Stock [Member]	Total
Balances at Dec. 31, 2020	$ 1,671	$ 408,244	$ 4,984,739	$ (2,794,516)	$ 2,600,138
Net earnings	0	0	146,606	0	146,606
Cash dividend declared and paid	0	0	(29,597)	0	(29,597)
Purchase of treasury shares	0	0	0	(5,239)	(5,239)
Share-based compensation	0	14,967	0	0	14,967
Restricted share issuances, net of stock repurchased for payroll taxes and other	0	(3,960)	0	(849)	(4,809)
Balances at Mar. 31, 2021	1,671	419,251	5,101,748	(2,800,604)	2,722,066
Balances at Dec. 31, 2021	1,671	448,217	5,621,103	(2,953,175)	3,117,816
Net earnings	0	0	243,325	0	243,325
Cash dividend declared and paid	0	0	(41,940)	0	(41,940)
Purchase of treasury shares	0	0	0	(75,018)	(75,018)
Share-based compensation	0	19,141	0	0	19,141
Restricted share issuances, net of stock repurchased for payroll taxes and other	0	(5,842)	0	(3,940)	(9,782)
Balances at Mar. 31, 2022	$ 1,671	$ 461,516	$ 5,822,488	$ (3,032,133)	$ 3,253,542