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, 2018	15,202,387
Balance at Dec. 31, 2018	$ 15	$ 55,859	$ 103,032	$ (7,985)	$ 150,921
Common shares issued upon exercise of options, net (in shares)	62,994
Common shares issued upon exercise of options, net		460	(177)		283
Cash dividends declared			(4,533)		(4,533)
Common stock reacquired and retired (in shares)	(73,893)
Common stock reacquired and retired		(269)	(974)		(1,243)
Net earnings			9,078		9,078
Cash flow hedges, net of taxes				(16)	(16)
Pensions, net of taxes				1,198	1,198
Change in currency translation adjustment, net of taxes				(295)	(295)
Share-based compensation expense		997			997
Balance (in shares) at Sep. 30, 2019	15,240,317
Balance at Sep. 30, 2019	$ 15	57,077	106,426	(7,098)	156,420
Restricted shares issued (in shares)	48,829
Tax benefit from vesting of acquisition-related restricted stock		30			30
Balance (in shares) at Jun. 30, 2019	15,255,694
Balance at Jun. 30, 2019	$ 15	57,166	104,165	(7,226)	154,120
Common shares issued upon exercise of options, net (in shares)	300
Common shares issued upon exercise of options, net		3			3
Share-based compensation expense		(35)			(35)
Cash dividends declared			(1,510)		(1,510)
Common stock reacquired and retired (in shares)	(15,677)
Common stock reacquired and retired		(57)	(150)		(207)
Net earnings			3,921		3,921
Cash flow hedges, net of taxes				(5)	(5)
Pensions, net of taxes				449	449
Change in currency translation adjustment, net of taxes				(316)	(316)
Balance (in shares) at Sep. 30, 2019	15,240,317
Balance at Sep. 30, 2019	$ 15	57,077	106,426	(7,098)	$ 156,420
Balance (in shares) at Dec. 31, 2019	15,227,604				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)	118,788				124,722
Common shares issued upon exercise of options, net		1,590	(183)		$ 1,407
Cash dividends declared			(4,574)		(4,574)
Common stock reacquired and retired (in shares)	(43,458)
Common stock reacquired and retired		(159)	(341)		(500)
Net earnings			28,485		28,485
Cash flow hedges, net of taxes				(16)	(16)
Pensions, net of taxes				1,026	1,026
Change in currency translation adjustment, net of taxes				(1,546)	(1,546)
Share-based compensation expense		1,790			1,790
Tax withheld on exercise of Stock Appreciation Rights (SARS)		(32)			$ (32)
Balance (in shares) at Sep. 30, 2020	15,340,949				15,340,949
Balance at Sep. 30, 2020	$ 15	60,618	130,968	(8,020)	$ 183,581
Restricted shares issued (in shares)	38,015
Tax benefit from vesting of acquisition-related restricted stock		(13)			(13)
Balance (in shares) at Jun. 30, 2020	15,231,781
Balance at Jun. 30, 2020	$ 15	58,381	124,243	(8,164)	174,475
Common shares issued upon exercise of options, net (in shares)	109,168
Common shares issued upon exercise of options, net		1,540	(166)		1,374
Cash dividends declared			(3,053)		(3,053)
Net earnings			9,944		9,944
Cash flow hedges, net of taxes				(5)	(5)
Pensions, net of taxes				294	294
Change in currency translation adjustment, net of taxes				(145)	(145)
Share-based compensation expense		729			729
Tax withheld on exercise of Stock Appreciation Rights (SARS)		(32)			$ (32)
Balance (in shares) at Sep. 30, 2020	15,340,949				15,340,949
Balance at Sep. 30, 2020	$ 15	$ 60,618	$ 130,968	$ (8,020)	$ 183,581