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	318,768	0	318,768
Cash dividend declared and paid	0	0	(61,301)	0	(61,301)
Purchase of treasury shares	0	0	0	(86,580)	(86,580)
Share-based compensation	0	31,466	0	0	31,466
Restricted share issuances, net of stock repurchased for payroll taxes and other	0	(2,974)	0	(489)	(3,463)
Balances at Jun. 30, 2021	1,671	436,736	5,242,206	(2,881,585)	2,799,028
Balances at Mar. 31, 2021	1,671	419,251	5,101,748	(2,800,604)	2,722,066
Net earnings	0	0	172,162	0	172,162
Cash dividend declared and paid	0	0	(31,704)	0	(31,704)
Purchase of treasury shares	0	0	0	(81,341)	(81,341)
Share-based compensation	0	16,498	0	0	16,498
Restricted share issuances, net of stock repurchased for payroll taxes and other	0	987	0	360	1,347
Balances at Jun. 30, 2021	1,671	436,736	5,242,206	(2,881,585)	2,799,028
Balances at Dec. 31, 2021	1,671	448,217	5,621,103	(2,953,175)	3,117,816
Net earnings	0	0	498,666	0	498,666
Cash dividend declared and paid	0	0	(83,674)	0	(83,674)
Purchase of treasury shares	0	0	0	(239,340)	(239,340)
Share-based compensation	0	39,584	0	0	39,584
Restricted share issuances, net of stock repurchased for payroll taxes and other	0	(4,692)	0	(3,496)	(8,188)
Balances at Jun. 30, 2022	1,671	483,109	6,036,095	(3,196,011)	3,324,864
Balances at Mar. 31, 2022	1,671	461,516	5,822,488	(3,032,133)	3,253,542
Net earnings	0	0	255,342	0	255,342
Cash dividend declared and paid	0	0	(41,735)	0	(41,735)
Purchase of treasury shares	0	0	0	(164,322)	(164,322)
Share-based compensation	0	20,443	0	0	20,443
Restricted share issuances, net of stock repurchased for payroll taxes and other	0	1,150	0	444	1,594
Balances at Jun. 30, 2022	$ 1,671	$ 483,109	$ 6,036,095	$ (3,196,011)	$ 3,324,864