Consolidated Statements of Stockholders' Equity - USD ($) shares in Thousands, $ in Thousands	Total	Cumulative-Effect Adjustments for Adoption of Accounting Principle	Common Stock	Additional Paid-in Capital	Retained Earnings	Retained Earnings Cumulative-Effect Adjustments for Adoption of Accounting Principle	Treasury Stock	Accumulated Other Comprehensive Loss
Balance at Dec. 31, 2018	$ 660,417		$ 22	$ 326,208	$ 486,442		$ (139,704)	$ (12,551)
Balance (in shares) at Dec. 31, 2018			18,817				3,629
Net income	68,938				68,938
Other comprehensive income	407							407
Equity compensation	15,818			15,818
Exercise of stock options	2,924			2,924
Exercise of stock options (in shares)			94
Issuance of shares pursuant to vesting of restricted stock units	1		$ 1
Issuance of shares pursuant to vesting of restricted stock units (in shares)			306
Net payments for stock issuances and buybacks	(23,414)			1,845			$ (25,259)
Net payments for stock issuances and buybacks (in shares)			(349)				349
Balance at Dec. 31, 2019	714,551		$ 23	346,795	544,840		$ (164,963)	(12,144)
Dividends declared	(10,540)				(10,540)
Balance (in shares) at Dec. 31, 2019			18,868				3,978
Net income	54,959				54,959
Other comprehensive income	(1,962)							(1,962)
Equity compensation	17,555			17,555
Exercise of stock options	2,652			2,652
Exercise of stock options (in shares)			70
Issuance of shares pursuant to vesting of restricted stock units (in shares)			389
Net payments for stock issuances and buybacks	(29,726)			2,056			$ (31,782)
Net payments for stock issuances and buybacks (in shares)			(417)				417
Balance at Dec. 31, 2020	746,961	$ (513)	$ 23	369,058	588,731	$ (513)	$ (196,745)	(14,106)
Accounting Standards Update Extensible List		us-gaap:AccountingStandardsUpdate201613Member				us-gaap:AccountingStandardsUpdate201613Member
Dividends declared	(10,555)				(10,555)
Balance (in shares) at Dec. 31, 2020			18,910				4,395
Net income	71,132				71,132
Other comprehensive income	3,071							3,071
Equity compensation	13,230			13,230
Exercise of stock options	233			233
Exercise of stock options (in shares)			8
Issuance of shares pursuant to vesting of restricted stock units (in shares)			222
Net payments for stock issuances and buybacks	(20,592)			2,463			$ (23,055)
Net payments for stock issuances and buybacks (in shares)			(264)				264
Balance at Dec. 31, 2021	803,470		$ 23	$ 384,984	649,298		$ (219,800)	$ (11,035)
Dividends declared	$ (10,565)				$ (10,565)
Balance (in shares) at Dec. 31, 2021			18,876				4,659