CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY - USD ($) shares in Thousands, $ in Thousands	Common Stock Cumulative Effect, Period of Adoption, Adjusted Balance	Common Stock	Additional Paid-In Capital Cumulative Effect, Period of Adoption, Adjusted Balance	Additional Paid-In Capital	Retained Earnings Cumulative Effect, Period of Adoption, Adjustment	Retained Earnings Cumulative Effect, Period of Adoption, Adjusted Balance	Retained Earnings	Treasury Stock Cumulative Effect, Period of Adoption, Adjusted Balance	Treasury Stock	Accumulated Other Comprehensive Income (Loss) Cumulative Effect, Period of Adoption, Adjustment	Accumulated Other Comprehensive Income (Loss) Cumulative Effect, Period of Adoption, Adjusted Balance	Accumulated Other Comprehensive Income (Loss)	Cumulative Effect, Period of Adoption, Adjustment	Cumulative Effect, Period of Adoption, Adjusted Balance	Total
Balances at Dec. 31, 2017	$ 285	$ 285	$ 319,436	$ 319,436	$ 3,992	$ 442,371	$ 438,379	$ (86,064)	$ (86,064)	$ (3,576)	$ (24,150)	$ (20,574)	$ 416	$ 651,878	$ 651,462
Balances (in shares) at Dec. 31, 2017	28,496	28,496						2,852	2,852
Increase (Decrease) in Stockholders' Equity
Net income							67,262								67,262
Other comprehensive income (loss) net of tax												9,912			9,912
Issuance of common stock under share-based compensation plans		$ 2		(2)
Issuance of common stock under share-based compensation plans (in shares)		189
Tax effect of share-based compensation plans				(2,135)											(2,135)
Share-based compensation expense				8,413											8,413
Purchase of treasury stock									$ (9,404)						(9,404)
Purchase of treasury stock (in shares)									246
Dividends declared on common stock							(8,244)								(8,244)
Balances at Dec. 31, 2018		$ 287		325,712			501,389		$ (95,468)			(14,238)			717,682
Balances (in shares) at Dec. 31, 2018		28,685							3,098
Increase (Decrease) in Stockholders' Equity
Net income							39,985								39,985
Other comprehensive income (loss) net of tax												14,441			14,441
Issuance of common stock under share-based compensation plans		$ 1		(1)
Issuance of common stock under share-based compensation plans (in shares)		126
Tax effect of share-based compensation plans				(1,291)											(1,291)
Share-based compensation expense				9,523											9,523
Purchase of treasury stock									$ (9,110)						(9,110)
Purchase of treasury stock (in shares)									307
Dividends declared on common stock							(8,187)								(8,187)
Balances at Dec. 31, 2019	$ 288	$ 288	$ 333,943	333,943	$ (198)	$ 532,989	533,187	$ (104,578)	$ (104,578)		$ 203	203	$ (198)	$ 762,845	763,043
Balances (in shares) at Dec. 31, 2019	28,811	28,811						3,405	3,405
Increase (Decrease) in Stockholders' Equity
Net income							71,100								71,100
Other comprehensive income (loss) net of tax												987			987
Issuance of common stock under share-based compensation plans		$ 2		(2)
Issuance of common stock under share-based compensation plans (in shares)		234
Tax effect of share-based compensation plans				(2,065)											(2,065)
Share-based compensation expense				10,478											10,478
Purchase of treasury stock									$ (6,595)						(6,595)
Purchase of treasury stock (in shares)									252
Dividends declared on common stock							(8,157)								(8,157)
Balances at Dec. 31, 2020		$ 290		$ 342,354			$ 595,932		$ (111,173)			$ 1,190			$ 828,593
Balances (in shares) at Dec. 31, 2020		29,045							3,657