Consolidated Statements of Shareholders' Equity - USD ($) $ in Thousands	Stock Appreciation Rights (SARs) [Member] Common Stock [Member]	Stock Appreciation Rights (SARs) [Member] Additional Paid-in Capital [Member]	Stock Appreciation Rights (SARs) [Member] Retained Earnings [Member]	Stock Appreciation Rights (SARs) [Member] AOCI Attributable to Parent [Member]	Stock Appreciation Rights (SARs) [Member]	Restricted Stock [Member] Common Stock [Member]	Restricted Stock [Member] Additional Paid-in Capital [Member]	Restricted Stock [Member] Retained Earnings [Member]	Restricted Stock [Member] AOCI Attributable to Parent [Member]	Restricted Stock [Member]	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	AOCI Attributable to Parent [Member]	Total
Balance (in shares) at Dec. 31, 2015											13,917,465
Balance at Dec. 31, 2015											$ 14	$ 33,806	$ 65,392	$ (6,522)	$ 92,690
Common shares issued upon exercise of options, net (in shares)											251,996
Common shares issued upon exercise of options, net											$ 1	1,960	(457)		1,504
Restricted shares issued (in shares)											333,190
Restricted shares issued												4,558			4,558
Common shares issued upon exercise of Stock Appreciation Rights (SARs) (in shares)											55,656
Share-based compensation expense												1,638			$ 1,638
Tax withheld on exercise of Stock Appreciation Rights (SARs)		$ (405)			$ (405)
Tax benefit from vesting of acquisition related restricted stock							$ 990			$ 990
Purchase and retirement of common shares (in shares)											(45,100)				(45,100)
Purchase and retirement of common shares												(131)	(583)		$ (714)
Cash dividends declared													(4,707)		(4,707)
Net income													14,638		14,638
Cash flow hedges, net of taxes														95	95
Pensions, net of taxes														190	190
Change in currency translation adjustment, net of taxes														73	73
Comprehensive Income:															14,996
Balance (in shares) at Dec. 31, 2016											14,513,207
Balance at Dec. 31, 2016											$ 15	42,416	74,283	(6,164)	$ 110,550
Common shares issued upon exercise of options, net (in shares)											285,745				336,726
Common shares issued upon exercise of options, net												2,779	(907)		$ 1,872
Restricted shares issued (in shares)											181,399
Restricted shares issued												2,780			2,780
Common shares issued upon exercise of Stock Appreciation Rights (SARs) (in shares)											101,596
Share-based compensation expense												1,664			1,664
Tax withheld on exercise of Stock Appreciation Rights (SARs)												(1,186)			(1,186)
Tax benefit from vesting of acquisition related restricted stock												650			$ 650
Purchase and retirement of common shares (in shares)															0
Cash dividends declared													(5,269)		$ (5,269)
Net income													15,022		15,022
Cash flow hedges, net of taxes														(111)	(111)
Pensions, net of taxes														(1,024)	(1,024)
Change in currency translation adjustment, net of taxes														20	20
Comprehensive Income:															$ 13,907
Balance (in shares) at Dec. 31, 2017											15,081,947				15,081,947
Balance at Dec. 31, 2017											$ 15	49,103	83,129	(7,279)	$ 124,968
Common shares issued upon exercise of options, net (in shares)											87,347				94,241
Common shares issued upon exercise of options, net												878	(151)		$ 727
Restricted shares issued (in shares)											150,094
Restricted shares issued												3,762			3,762
Common shares issued upon exercise of Stock Appreciation Rights (SARs) (in shares)											3,428
Share-based compensation expense												2,264			2,264
Tax withheld on exercise of Stock Appreciation Rights (SARs)												(17)			(17)
Tax benefit from vesting of acquisition related restricted stock												445			$ 445
Purchase and retirement of common shares (in shares)															(158,359)
Cash dividends declared													(5,836)		$ (5,836)
Net income													16,975		16,975
Cash flow hedges, net of taxes														203	203
Pensions, net of taxes														(391)	(391)
Change in currency translation adjustment, net of taxes														(518)	(518)
Comprehensive Income:															16,269
ASC 606 adjustment to opening retained earnings													11,245		11,245
Common shares repurchased (in shares)											(158,359)
Common shares repurchased												(576)	(2,330)		$ (2,906)
Balance (in shares) at Dec. 31, 2018											15,202,387				15,202,387
Balance at Dec. 31, 2018											$ 15	$ 55,859	$ 103,032	$ (7,985)	$ 150,921