Condensed Consolidated Statements of Shareholders' Equity (Unaudited) - USD ($) $ in Thousands	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	AOCI Attributable to Parent [Member]	Total
Balance (in shares) at Dec. 31, 2019	15,227,604
Balance at Dec. 31, 2019	$ 15	$ 57,442	$ 107,581	$ (7,484)	$ 157,554
Common shares issued upon exercise of options, net (in shares)	9,620
Common shares issued upon exercise of options, net		50	(17)		33
Share-based compensation expense		1,061			1,061
Net income			18,541		18,541
Cash flow hedges, net of taxes				(11)	(11)
Pensions, net of taxes				732	732
Change in currency translation adjustment, net of taxes				(1,401)	(1,401)
Restricted shares issued (in shares)	38,015
Restricted shares issued					0
Cash dividends declared			(1,521)		(1,521)
Tax benefit from vesting of acquisition-related restricted stock		(13)			(13)
Common stock reacquired and retired (in shares)	(43,458)
Common stock reacquired and retired		(159)	(341)		(500)
Balance (in shares) at Jun. 30, 2020	15,231,781
Balance at Jun. 30, 2020	$ 15	58,381	124,243	(8,164)	174,475
Balance (in shares) at Mar. 31, 2020	15,222,161
Balance at Mar. 31, 2020	$ 15	57,669	109,086	(8,380)	158,390
Common shares issued upon exercise of options, net (in shares)	9,620
Common shares issued upon exercise of options, net		50	(17)		33
Share-based compensation expense		662			662
Net income			15,174		15,174
Cash flow hedges, net of taxes				(6)	(6)
Pensions, net of taxes				384	384
Change in currency translation adjustment, net of taxes				(162)	(162)
Balance (in shares) at Jun. 30, 2020	15,231,781
Balance at Jun. 30, 2020	$ 15	58,381	124,243	(8,164)	$ 174,475
Balance (in shares) at Dec. 31, 2020	15,391,660				15,391,660
Balance at Dec. 31, 2020	$ 15	61,844	141,972	(12,201)	$ 191,630
Common shares issued upon exercise of options, net (in shares)	230,158				234,092
Common shares issued upon exercise of options, net	$ 1	2,299	(178)		$ 2,122
Share-based compensation expense		1,669			1,669
Net income			16,855		16,855
Cash flow hedges, net of taxes				(11)	(11)
Pensions, net of taxes				6,335	6,335
Change in currency translation adjustment, net of taxes				386	386
Performance based shares issued (in shares)	42,823
Performance based shares issued					0
Restricted shares issued (in shares)	159,889
Restricted shares issued					0
Tax withheld on exercise of performance based shares		(405)			(405)
Cash dividends declared			(3,437)		(3,437)
Tax benefit from vesting of acquisition-related restricted stock		171			$ 171
Balance (in shares) at Jun. 30, 2021	15,824,530				15,824,530
Balance at Jun. 30, 2021	$ 16	65,578	155,212	(5,491)	$ 215,315
Balance (in shares) at Mar. 31, 2021	15,582,835
Balance at Mar. 31, 2021	$ 15	62,773	150,734	(12,139)	201,383
Share-based compensation expense		837			837
Net income			6,377		6,377
Cash flow hedges, net of taxes				(6)	(6)
Pensions, net of taxes				5,621	5,621
Change in currency translation adjustment, net of taxes				1,033	1,033
Common shares issued upon exercise of options and SARs, net (in shares)	219,412
Common shares issued upon exercise of options and SARs, net	$ 1	2,001	(10)		1,992
Performance based shares issued (in shares)	3,148
Performance based shares issued					0
Restricted shares issued (in shares)	19,135
Restricted shares issued					0
Tax withheld on exercise of performance based shares		(33)			(33)
Cash dividends declared			(1,889)		$ (1,889)
Balance (in shares) at Jun. 30, 2021	15,824,530				15,824,530
Balance at Jun. 30, 2021	$ 16	$ 65,578	$ 155,212	$ (5,491)	$ 215,315