Consolidated Statements of Stockholders' Equity (USD $) In Thousands, unless otherwise specified	Common Stock [Member]	Paid-in Capital [Member]	Retained Earnings [Member]	Treasury Stock [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Total
Balance, at Dec. 31, 2008	$ 111	$ 47,585	$ 197,060	$ (26,482)	$ (712)	$ 217,562
Net income			15,727			15,727
Other comprehensive (loss) income net of tax:
Pension liability adjustment					292	292
Unrealized derivative loss on cash flow hedges					23	23
Market value adjustments for investments					5	5
Comprehensive income						16,047
Purchase of Common shares for Treasury				(1,863)		(1,863)
Issuance of Common Shares, net of forfeitures		75		771		846
Balance, at Dec. 31, 2009	111	47,660	212,787	(27,574)	(392)	232,592
Net income			20,492			20,492
Other comprehensive (loss) income net of tax:
Pension liability adjustment					(74)	(74)
Unrealized derivative loss on cash flow hedges					11	11
Foreign currency translation adjustment					117	117
Market value adjustments for investments					(730)	(730)
Comprehensive income						19,816
Purchase of Common shares for Treasury				(17)		(17)
Issuance of Common Shares, net of forfeitures		(374)		3,730		3,356
Balance, at Dec. 31, 2010	111	47,286	233,279	(23,861)	(1,068)	255,747
Net income			22,895			22,895
Other comprehensive (loss) income net of tax:
Pension liability adjustment					(2,254)	(2,254)
Foreign currency translation adjustment					(1,306)	(1,306)
Comprehensive income						19,335
Purchase of Common shares for Treasury				(6,480)		(6,480)
Issuance of Common Shares, net of forfeitures		63		2,172		2,235
Cash dividends on common stock paid to shareholders			(1,022)			(1,022)
Balance, at Dec. 31, 2011	$ 111	$ 47,349	$ 255,152	$ (28,169)	$ (4,628)	$ 269,815