Quarterly Financial Information (Unaudited) (Tables) (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended										12 Months Ended
	Dec. 31, 2012	Sep. 30, 2012		Jun. 30, 2012		Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Net Sales	$ 140,724	$ 170,346	[1]	$ 163,180	[2]	$ 114,291	$ 133,735	$ 158,323	$ 169,591	$ 113,688	$ 588,541	$ 575,337	$ 467,058
Gross profit	27,570	30,713	[1]	12,334	[2]	21,652	26,524	29,594	25,306	16,986	92,269	98,410	72,861
Income from continuing operations	6,643	8,463	[1]	(3,321)	[2]	2,979	5,817	9,351	6,294	605	14,764	22,067	20,006
Income from discontinued operations	22	(238)	[1]	1,250	[2]	390	286	389	229	(76)	1,424	828	486
Net income	6,665	8,225	[1]	(2,071)	[2]	3,369	6,103	9,740	6,523	529	16,188	22,895	20,492
Basic earnings per common share: From continuing operations	$ 0.650	$ 0.830	[1]	$ (0.330)	[2]	$ 0.300	$ 0.58	$ 0.92	$ 0.61	$ 0.06	$ 1.46	$ 2.16	$ 1.96
Basic earnings per common share: From discontinued operations		$ (0.020)	[1]	$ 0.120	[2]	$ 0.040	$ 0.03	$ 0.04	$ 0.02	$ (0.01)	$ 0.14	$ 0.08	$ 0.05
Basic earnings per common share	$ 0.660	$ 0.810	[1]	$ (0.200)	[2]	$ 0.330	$ 0.61	$ 0.96	$ 0.63	$ 0.05	$ 1.60	$ 2.24	$ 2.01
Diluted earnings per common share: From continuing operations	$ 0.650	$ 0.830	[1]	$ (0.330)	[2]	$ 0.290	$ 0.57	$ 0.91	$ 0.60	$ 0.06	$ 1.44	$ 2.14	$ 1.93
Diluted earnings per common share: From discontinued operations		$ (0.020)	[1]	$ 0.120	[2]	$ 0.040	$ 0.03	$ 0.04	$ 0.02	$ (0.01)	$ 0.14	$ 0.08	$ 0.05
Diluted earnings per common share	$ 0.650	$ 0.810	[1]	$ (0.200)	[2]	$ 0.320	$ 0.60	$ 0.95	$ 0.63	$ 0.05	$ 1.58	$ 2.22	$ 1.98
Dividends paid per common share	$ 0.025	$ 0.025	[1]	$ 0.025	[2]	$ 0.025	$ 0.025	$ 0.025	$ 0.050		$ 0.10	$ 0.10
Sale Leaseback Transaction, Cumulative Gain Recognized	577							577			577
Sale Of SSD [Member]
Significant Acquisitions and Disposals, Gain (Loss) on Sale or Disposal, Pretax				3,508
Sale Of Precise [Member]
Significant Acquisitions and Disposals, Gain (Loss) on Sale or Disposal, Pretax		$ 315

[1] Includes a pre-tax loss of approximately $315,000 from the Company’s sale of Precise

[2] Includes a pre-tax gain of approximately $3,508,000 from the Company’s sale of SSD.