Statements of Changes in Shareholders' Equity - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock [Member]	Capital In Excess Of Par Value [Member]	Retained Earnings [Member]
Balance at Dec. 31, 2018	$ 2,680,483	$ 12,185	$ 138,210	$ 2,530,088
Balance, in shares at Dec. 31, 2018		121,847
Net income	615,518			615,518
Share repurchases	(240,960)	$ (240)		(240,720)
Share repurchases, shares		(2,403)
Cash dividends declared	(54,584)			(54,584)
Reclassification of liability for modified equity awards	64,991		64,991
Share-based compensation and share issuances, net of forfeitures	16,717	$ 10	16,707
Share-based compensation and share issuances, net of forfeitures, shares		104
Taxes paid in exchange for shares withheld	(1,448)	$ (2)	(1,446)
Taxes paid in exchange for shares withheld, shares		(15)
Balance at Dec. 31, 2019	3,080,717	$ 11,953	218,462	2,850,302
Balance, in shares at Dec. 31, 2019		119,533
Net income	672,682			672,682
Share repurchases	(364,057)	$ (250)		(363,807)
Share repurchases, shares		(2,508)
Cash dividends declared	(71,046)			(71,046)
Cash paid for fractional shares	(612)	$ (1)	(611)
Cash paid for fractional shares, shares		(5)
Share-based compensation and share issuances, net of forfeitures	11,337	$ 6	11,331
Share-based compensation and share issuances, net of forfeitures, shares		57
Taxes paid in exchange for shares withheld	(2,733)	$ (2)	(2,731)
Taxes paid in exchange for shares withheld, shares		(19)
Balance at Dec. 31, 2020	3,326,288	$ 11,706	226,451	3,088,131
Balance, in shares at Dec. 31, 2020		117,058
Net income	1,034,375			1,034,375
Share repurchases	(536,465)	$ (209)		(536,256)
Share repurchases, shares		(2,083)
Forward contract for accelerated share repurchases	(62,500)		(62,500)
Cash dividends declared	(92,389)			(92,389)
Share-based compensation and share issuances, net of forfeitures	15,039	$ 6	15,033
Share-based compensation and share issuances, net of forfeitures, shares		57
Taxes paid in exchange for shares withheld	(4,541)	$ (2)	(4,539)
Taxes paid in exchange for shares withheld, shares		(21)
Balance at Dec. 31, 2021	$ 3,679,807	$ 11,501	$ 174,445	$ 3,493,861
Balance, in shares at Dec. 31, 2021		115,011