Statement of Stockholders Equity - USD ($)	Common Stock [Member] Employee Stock Option [Member]	Common Stock [Member] Stock Appreciation Rights (SARs) [Member]	Common Stock [Member]	Additional Paid-in Capital [Member] Employee Stock Option [Member]	Additional Paid-in Capital [Member] Stock Appreciation Rights (SARs) [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member] Employee Stock Option [Member]	Retained Earnings [Member] Stock Appreciation Rights (SARs) [Member]	Retained Earnings [Member]	AOCI Attributable to Parent [Member] Employee Stock Option [Member]	AOCI Attributable to Parent [Member] Stock Appreciation Rights (SARs) [Member]	AOCI Attributable to Parent [Member]	Employee Stock Option [Member]	Stock Appreciation Rights (SARs) [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)			340,062										40,816		360,318
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	$ 32,000								$ 231,000	$ 32,000
Cash dividends declared									$ (3,663,000)						(3,663,000)
Net income									$ 11,349,000						11,349,000
Cash flow hedges, net of taxes												$ 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												13,514,566
Balance, at Dec. 31, 2014			$ 13,000			$ 29,501,000			$ 56,843,000			$ (5,945,000)			$ 80,412,000
Gain (loss) on cash flow hedging activities												(26,000)			(26,000)
Pensions, net of taxes												$ 2,705,000			$ 2,705,000
Common shares issued upon exercise of options, net (in shares)			294,659										50,224		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	$ 225,000								$ 618,000	$ 225,000
Cash dividends declared									$ (4,255,000)						(4,255,000)
Net income									$ 13,066,000						13,066,000
Cash flow hedges, net of taxes												$ (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
Gain (loss) on cash flow hedging activities												37,000			37,000
Pensions, net of taxes												$ (614,000)			$ (614,000)