CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY - USD ($) shares in Thousands, $ in Thousands	Common Stock	Additional Paid-In Capital	Retained Earnings	Treasury Stock	Accumulated Other Comprehensive Income (Loss)	Total
Balances at Dec. 31, 2016	$ 282	$ 315,318	$ 386,917	$ (80,045)	$ (23,417)	$ 599,055
Balances (in shares) at Dec. 31, 2016	28,174			2,565
Increase (Decrease) in Stockholders' Equity
Net income			59,726			59,726
Other comprehensive income, net of tax					2,843	2,843
Issuance of common stock under share-based compensation plans	$ 3	(3)
Issuance of common stock under share-based compensation plans (in shares)	322
Tax effect of share-based compensation plans		(2,837)				(2,837)
Share-based compensation expense		6,958				6,958
Purchase of treasury stock				$ (6,019)		(6,019)
Purchase of treasury stock (in shares)				287
Dividends declared on common stock			(8,264)			(8,264)
Balances at Dec. 31, 2017	$ 285	319,436	438,379	$ (86,064)	(20,574)	651,462
Balances (in shares) at Dec. 31, 2017	28,496			2,852
Increase (Decrease) in Stockholders' Equity
Adjustments to beginning retained earnings for adoption of accounting standards | ASC Topic 606 and ASC Topic 220			3,992		(3,576)	416
Adjustments to beginning retained earnings for adoption of accounting standards					(3,576)
Adjusted Balances	$ 285	319,436	442,371	$ (86,064)	(24,150)	651,878
Net income			67,262			67,262
Other comprehensive income, 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, 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	$ 333,943	$ 533,187	$ (104,578)	$ 203	$ 763,043
Balances (in shares) at Dec. 31, 2019	28,811			3,405