CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY - USD ($) shares in Thousands, $ in Thousands	Common Stock	Additional Paid-In Capital	Retained Earnings	Treasury Stock	Accumulated Other Comprehensive Loss	Total
Increase (Decrease) in Stockholders' Equity
Adjustments to beginning retained earnings for adoption of accounting standards			$ 3,992		$ (3,576)	$ 416
Adjusted Balances	$ 285	$ 319,436	442,371	$ (86,064)	(24,150)	651,878
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
Net income			9,954			9,954
Other comprehensive income, net of tax					4,072	4,072
Issuance of common stock under share-based compensation plans (in shares)	3
Tax effect of share-based compensation plans		(41)				(41)
Share-based compensation expense		1,870				1,870
Purchase of treasury stock				$ (201)		(201)
Purchase of treasury stock (in shares)				5
Dividends declared on common stock			(2,058)			(2,058)
Balances at Mar. 31, 2018	$ 285	321,265	450,267	$ (86,265)	(20,078)	665,474
Balances (in shares) at Mar. 31, 2018	28,499			2,857
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			4,888			4,888
Other comprehensive income, net of tax					1,850	1,850
Tax effect of share-based compensation plans		(8)				(8)
Share-based compensation expense		2,058				2,058
Purchase of treasury stock				$ (2,663)		(2,663)
Purchase of treasury stock (in shares)				74
Dividends declared on common stock			(2,052)			(2,052)
Balances at Mar. 31, 2019	$ 287	$ 327,762	$ 504,225	$ (98,131)	$ (12,388)	$ 721,755
Balances (in shares) at Mar. 31, 2019	28,685			3,172