Consolidated Statements of Stockholders' Equity - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Retained Earnings	Accumulated Other Comprehensive Loss
Beginning Balance (in shares) at Dec. 31, 2018		38,147
Beginning Balance at Dec. 31, 2018	$ 1,348,825	$ 381	$ 299,534	$ 1,196,727	$ (147,817)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	216,726			216,726
Other comprehensive income (loss):
Cumulative translation adjustment	6,970				6,970
Issuance of common stock in connection with:
Exercise of options (in shares)		256
Exercise of options	9,688	$ 3	9,685
Restricted share grants (in shares)		245
Restricted share grants	(6,517)	$ 3	(6,520)
Stock units issued under incentive compensation plan	1,413		1,413
Purchase and retirement of common stock (in shares)		(1,258)
Purchase and retirement of common stock	(105,941)	$ (13)	(105,928)
Share-based compensation	17,978		17,978
Ending Balance (in shares) at Dec. 31, 2019		37,390
Ending Balance at Dec. 31, 2019	1,489,142	$ 374	216,162	1,413,453	(140,847)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	210,682			210,682
Other comprehensive income (loss):
Cumulative translation adjustment	34,412				34,412
Issuance of common stock in connection with:
Exercise of options (in shares)		140
Exercise of options	4,934	$ 1	4,933
Restricted share grants (in shares)		220
Restricted share grants	(10,756)	$ 3	(10,759)
Stock units issued under incentive compensation plan	2,314		2,314
Purchase and retirement of common stock (in shares)		(3,269)
Purchase and retirement of common stock	(353,451)	$ (33)	(235,554)	(117,864)
Share-based compensation	$ 22,904		22,904
Ending Balance (in shares) at Dec. 31, 2020	34,481	34,481
Ending Balance at Dec. 31, 2020	$ 1,400,181	$ 345	0	1,506,271	(106,435)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	234,966			234,966
Other comprehensive income (loss):
Cumulative translation adjustment	$ (22,405)				(22,405)
Issuance of common stock in connection with:
Exercise of options (in shares)	78	78
Exercise of options	$ 2,694	$ 1	2,693
Restricted share grants (in shares)		196
Restricted share grants	(11,635)	$ 1	(11,636)
Stock units issued under incentive compensation plan	2,603		2,603
Purchase and retirement of common stock (in shares)		(422)
Purchase and retirement of common stock	(46,132)	$ (4)	(3,047)	(43,081)
Conversion feature of convertible senior notes due 2023, net	(2)		(2)
Share-based compensation	$ 23,051		23,051
Ending Balance (in shares) at Dec. 31, 2021	34,333	34,333
Ending Balance at Dec. 31, 2021	$ 1,583,321	$ 343	$ 13,662	$ 1,698,156	$ (128,840)