Consolidated Statements of Shareholders' Equity - USD ($)	Employee Stock Option [Member] Common Stock [Member]	Employee Stock Option [Member] Additional Paid-in Capital [Member]	Employee Stock Option [Member] Retained Earnings [Member]	Employee Stock Option [Member] AOCI Attributable to Parent [Member]	Employee Stock Option [Member]	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, 2013																13,040,816
Balance at Dec. 31, 2013																$ 13,000	$ 25,821,000	$ 49,315,000	$ (3,214,000)	$ 71,935,000
Common shares issued upon exercise of options, net (in shares)					40,816											340,062
Common shares issued upon exercise of options, net																	2,013,000	(158,000)		1,855,000
Restricted shares issued (in shares)																106,016
Restricted shares issued																	229,000			229,000
Common shares issued upon exercise of Stock Appreciation Rights (SARs) (in shares)																27,672
Share-based compensation expense																	1,175,000			1,175,000
Excess benefit from exercise of stock options		$ 231,000			$ 231,000		$ 32,000			$ 32,000
Cash dividends declared																		(3,663,000)		(3,663,000)
Net income																		11,349,000		11,349,000
Gain (loss) on cash flow hedging activities																			(26,000)	(26,000)
Pensions, net of taxes																			(2,705,000)	(2,705,000)
Comprehensive income																				8,618,000
Balance (in shares) at Dec. 31, 2014																13,514,566
Balance at Dec. 31, 2014																$ 13,000	29,501,000	56,843,000	(5,945,000)	$ 80,412,000
Purchase and retirement of common shares (in shares)																				0
Common shares issued upon exercise of options, net (in shares)					50,224											294,659				309,230
Common shares issued upon exercise of options, net																$ 1,000	2,101,000	(262,000)		$ 1,840,000
Restricted shares issued (in shares)																8,326
Restricted shares issued																	282,000			282,000
Common shares issued upon exercise of Stock Appreciation Rights (SARs) (in shares)																99,914
Share-based compensation expense																	1,079,000			1,079,000
Excess benefit from exercise of stock options		$ 618,000			$ 618,000		225,000			225,000
Cash dividends declared																		(4,255,000)		(4,255,000)
Net income																		13,066,000		13,066,000
Gain (loss) on cash flow hedging activities																			37,000	37,000
Pensions, net of taxes																			(614,000)	(614,000)
Comprehensive income																				$ 12,489,000
Balance (in shares) at Dec. 31, 2015																13,917,465				13,917,465
Balance at Dec. 31, 2015																$ 14,000	33,806,000	65,392,000	(6,522,000)	$ 92,690,000
Purchase and retirement of common shares (in shares)																				0
Common shares issued upon exercise of options, net (in shares)					81,608											251,996				279,766
Common shares issued upon exercise of options, net																$ 1,000	1,960,000	(457,000)		$ 1,504,000
Restricted shares issued (in shares)																333,190
Restricted shares issued																	4,558,000			4,558,000
Common shares issued upon exercise of Stock Appreciation Rights (SARs) (in shares)																55,656
Share-based compensation expense																	1,638,000			1,638,000
Cash dividends declared																		(4,707,000)		(4,707,000)
Net income																		14,638,000		14,638,000
Gain (loss) on cash flow hedging activities																			95,000	95,000
Pensions, net of taxes																			190,000	190,000
Comprehensive income																				$ 14,996,000
Balance (in shares) at Dec. 31, 2016																14,513,207				14,513,207
Balance at Dec. 31, 2016																$ 15,000	42,416,000	74,283,000	(6,164,000)	$ 110,550,000
Tax withheld on exercise of Stock Appreciation Rights (SARs)							$ (405,000)			$ (405,000)
Tax benefit from vesting of acquisition related restricted stock												$ 990,000			$ 990,000
Purchase and retirement of common shares (in shares)																(45,100)				(45,100)
Purchase and retirement of common shares																	(131,000)	(583,000)		$ (714,000)
Change in currency translation adjustment, net of taxes																			$ 73,000	$ 73,000