Condensed Consolidated Statements of Changes in Stockholders' Equity - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-In Capital	Accumulated Other Comprehensive Loss, Net	Accumulated Earnings	Treasury Stock
Beginning balance at Dec. 31, 2019	$ 938,593	$ 82	$ 1,899,273	$ (77,938)	$ 1,988,722	$ (2,871,546)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	75,097				75,097
Other comprehensive income (loss)	(91,034)			(91,034)
Issuances under stock plans	5,654		(1,794)			7,448
Common share repurchases	(63,164)					(63,164)
Stock-based compensation expense	25,129		25,129
Ending balance at Mar. 31, 2020	890,275	82	1,922,608	(168,972)	2,063,819	(2,927,262)
Beginning balance at Dec. 31, 2019	938,593	82	1,899,273	(77,938)	1,988,722	(2,871,546)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	147,138
Other comprehensive income (loss)	(52,275)
Ending balance at Sep. 30, 2020	1,037,503	82	1,960,143	(130,213)	2,135,860	(2,928,369)
Beginning balance at Mar. 31, 2020	890,275	82	1,922,608	(168,972)	2,063,819	(2,927,262)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	55,077				55,077
Other comprehensive income (loss)	26,797			26,797
Issuances under stock plans	4,090		3,223			867
Common share repurchases	(698)					(698)
Stock-based compensation expense	15,678		15,678
Ending balance at Jun. 30, 2020	991,219	82	1,941,509	(142,175)	2,118,896	(2,927,093)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	16,964				16,964
Other comprehensive income (loss)	11,962			11,962
Issuances under stock plans	4,112		3,133			979
Common share repurchases	(2,255)					(2,255)
Stock-based compensation expense	15,501		15,501
Ending balance at Sep. 30, 2020	1,037,503	82	1,960,143	(130,213)	2,135,860	(2,928,369)
Beginning balance at Dec. 31, 2020	1,090,428	82	1,968,930	(99,228)	2,255,467	(3,034,823)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	164,100				164,100
Other comprehensive income (loss)	6,050			6,050
Issuances under stock plans	5,380		(1,543)			6,923
Common share repurchases	(410,450)					(410,450)
Stock-based compensation expense	36,086		36,086
Ending balance at Mar. 31, 2021	891,594	82	2,003,473	(93,178)	2,419,567	(3,438,350)
Beginning balance at Dec. 31, 2020	1,090,428	82	1,968,930	(99,228)	2,255,467	(3,034,823)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	584,201
Other comprehensive income (loss)	15,391
Ending balance at Sep. 30, 2021	334,507	82	2,054,563	(83,837)	2,839,668	(4,475,969)
Beginning balance at Mar. 31, 2021	891,594	82	2,003,473	(93,178)	2,419,567	(3,438,350)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	271,236				271,236
Other comprehensive income (loss)	10,200			10,200
Issuances under stock plans	4,080		2,063			2,017
Common share repurchases	(675,662)					(675,662)
Stock-based compensation expense	26,190		26,190
Ending balance at Jun. 30, 2021	527,638	82	2,031,726	(82,978)	2,690,803	(4,111,995)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	148,865				148,865
Other comprehensive income (loss)	(859)			(859)
Issuances under stock plans	4,131		3,411			720
Common share repurchases	(364,694)					(364,694)
Stock-based compensation expense	19,426		19,426
Ending balance at Sep. 30, 2021	$ 334,507	$ 82	$ 2,054,563	$ (83,837)	$ 2,839,668	$ (4,475,969)