Consolidated Statements of Stockholders' Equity (USD $) In Thousands, except Share data, unless otherwise specified	Total	Common Stock	Additional Paid-In Capital	Accumulated Other Comprehensive (Loss) Income	Retained Earnings	Treasury Stock	Comprehensive (Loss) Income
Balances at Dec. 31, 2009	$ 109,981	$ 640	$ 15,619	$ (2,718)	$ 96,684	$ (244)
Balances (in shares) at Dec. 31, 2009		6,393,581
Increase (Decrease) in Stockholders' Equity
Stock options exercised (in shares)		2,660
Stock-based compensation	737	2	735
Stock-based compensation (in shares)		18,635
Treasury shares purchased	(173)					(173)
Treasury shares purchased (in shares)		(4,476)
Net income	18,040				18,040		18,040
Minimum pension liability adjustments, net of tax expense (benefit) of $36, ($85) and $17, for 2012, 2011 and 2010, respectively	30			30			30
Mark to market of interest rate hedge, net of tax expense (benefit) of $312, $89 and ($182) for 2012, 2011 and 2010, respectively	(321)			(321)			(321)
Comprehensive income	17,749			(291)	18,040		17,749
Balances at Dec. 31, 2010	128,294	642	16,354	(3,009)	114,724	(417)
Balances (in shares) at Dec. 31, 2010		6,410,400
Increase (Decrease) in Stockholders' Equity
Stock options exercised		1	(1)
Stock options exercised (in shares)		11,244
Stock-based compensation	848	2	846
Stock-based compensation (in shares)		18,050
Treasury shares purchased	(8,323)					(8,323)
Treasury shares purchased (in shares)		(204,255)
Net income	22,186				22,186		22,186
Minimum pension liability adjustments, net of tax expense (benefit) of $36, ($85) and $17, for 2012, 2011 and 2010, respectively	(149)			(149)			(149)
Mark to market of interest rate hedge, net of tax expense (benefit) of $312, $89 and ($182) for 2012, 2011 and 2010, respectively	157			157			157
Comprehensive income	22,194			8	22,186		22,194
Balances at Dec. 31, 2011	143,013	645	17,199	(3,001)	136,910	(8,740)
Balances (in shares) at Dec. 31, 2011		6,235,439
Increase (Decrease) in Stockholders' Equity
Stock options exercised	75	1	74
Stock options exercised (in shares)		10,000
Stock-based compensation	1,082	2	1,080
Stock-based compensation (in shares)		16,992
Treasury shares purchased	(40,847)					(40,847)
Treasury shares purchased (in shares)		(704,429)
Net income	16,423				16,423		16,423
Minimum pension liability adjustments, net of tax expense (benefit) of $36, ($85) and $17, for 2012, 2011 and 2010, respectively	64			64			64
Mark to market of interest rate hedge, net of tax expense (benefit) of $312, $89 and ($182) for 2012, 2011 and 2010, respectively	545			545			545
Comprehensive income	17,032			609	16,423		17,032
Balances at Dec. 31, 2012	$ 120,355	$ 648	$ 18,353	$ (2,392)	$ 153,333	$ (49,587)
Balances (in shares) at Dec. 31, 2012		5,558,002