Condensed Statements of Changes in Shareholders' Equity (Unaudited) - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock [Member]	Capital In Excess Of Par Value [Member]	Retained Earnings [Member]
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	199,359			199,359
Share repurchases, including settlements under accelerated share repurchase programs, shares		(1,127)
Share repurchases, including settlements under accelerated share repurchase programs	(240,215)	$ (113)		(240,102)
Forward contract for accelerated share repurchases	(68,750)		(68,750)
Cash dividends declared	(23,193)			(23,193)
Share-based compensation and share issuances, net of forfeitures, shares		55
Share-based compensation and share issuances, net of forfeitures	2,969	$ 5	2,964
Taxes paid in exchange for shares withheld, shares		(21)
Taxes paid in exchange for shares withheld	(4,541)	$ (2)	(4,539)
Balance at Mar. 31, 2021	3,191,917	$ 11,596	156,126	3,024,195
Balance, in shares at Mar. 31, 2021		115,965
Net income	269,576			269,576
Share repurchases, including settlements under accelerated share repurchase programs, shares		(160)
Share repurchases, including settlements under accelerated share repurchase programs	(40,000)	$ (16)		(39,984)
Cash dividends declared	(23,194)			(23,194)
Share-based compensation and share issuances, net of forfeitures, shares		5
Share-based compensation and share issuances, net of forfeitures	4,079	$ 1	4,078
Balance at Jun. 30, 2021	3,402,378	$ 11,581	160,204	3,230,593
Balance, in shares at Jun. 30, 2021		115,810
Balance at Dec. 31, 2021	3,679,807	$ 11,501	174,445	3,493,861
Balance, in shares at Dec. 31, 2021		115,011
Net income	299,751			299,751
Share repurchases, including settlements under accelerated share repurchase programs, shares		(1,273)
Share repurchases, including settlements under accelerated share repurchase programs	(338,352)	$ (127)	62,500	(400,725)
Forward contract for accelerated share repurchases	(100,000)		(100,000)
Cash dividends declared	(34,128)			(34,128)
Share-based compensation and share issuances, net of forfeitures, shares		50
Share-based compensation and share issuances, net of forfeitures	4,291	$ 5	4,286
Taxes paid in exchange for shares withheld, shares		(27)
Taxes paid in exchange for shares withheld	(8,062)	$ (3)	(8,059)
Balance at Mar. 31, 2022	3,503,307	$ 11,376	133,172	3,358,759
Balance, in shares at Mar. 31, 2022		113,761
Net income	376,078			376,078
Share repurchases, including settlements under accelerated share repurchase programs, shares		1,530
Share repurchases, including settlements under accelerated share repurchase programs	(293,518)	$ (153)	100,000	(393,365)
Cash dividends declared	(33,858)			(33,858)
Share-based compensation and share issuances, net of forfeitures, shares		5
Share-based compensation and share issuances, net of forfeitures	3,882	$ 1	3,881
Taxes paid in exchange for shares withheld	(62)		(62)
Balance at Jun. 30, 2022	$ 3,555,829	$ 11,224	$ 236,991	$ 3,307,614
Balance, in shares at Jun. 30, 2022		112,236