Supplementary Information - Quarterly Results of Operations (Details) (USD $)	3 Months Ended																12 Months Ended
	Dec. 31, 2014		Sep. 30, 2014		Jun. 30, 2014		Mar. 31, 2014		Dec. 31, 2013		Sep. 30, 2013		Jun. 30, 2013		Mar. 31, 2013		Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Quarterly Financial Information Disclosure [Abstract]
Net sales	$ 94,931,000		$ 59,067,000		$ 48,546,000		$ 71,903,000		$ 77,091,000		$ 46,256,000		$ 36,242,000		$ 59,214,000		$ 274,447,000	$ 218,803,000	$ 193,926,000
Gross profit	48,519,000		28,795,000		24,780,000		38,481,000		36,677,000		21,777,000		17,329,000		30,694,000		140,575,000	106,477,000	91,037,000
Operating income (loss)	14,493,000		4,281,000		2,379,000		9,001,000		10,118,000		1,336,000		(1,724,000)		5,994,000		30,154,000	15,724,000	10,588,000
Income from continuing operations	10,473,000		2,664,000		1,498,000		5,748,000		8,432,000		1,500,000		32,668,000		5,524,000		20,383,000	48,124,000	10,642,000
Income (loss) from discontinued operation	(96,000)		(177,000)		(941,000)		(374,000)		116,000		(116,000)		195,000		(365,000)		(1,588,000)	(170,000)	6,241,000
Net income	10,377,000	[1]	2,487,000	[1]	557,000	[1]	5,374,000	[1]	8,548,000	[1]	1,384,000	[1]	32,863,000	[1]	5,159,000	[1]	18,795,000	47,954,000	16,883,000
Basic	$ 0.33		$ 0.08		$ 0.02		$ 0.17		$ 0.27		$ 0.04		$ 1.06		$ 0.17		$ 0.60	$ 1.54	$ 0.55
Diluted	$ 0.33		$ 0.08		$ 0.02		$ 0.17		$ 0.27		$ 0.04		$ 1.05		$ 0.17		$ 0.59	$ 1.52	$ 0.55
Income tax benefit due to reduction of existing valuation allowance	$ 1,200,000												$ 35,800,000					$ 38,900,000

[1] Net income in the quarters ended December 31, 2014 and June 30, 2013 included a $1.2 million and a $35.8 million credit, respectively, related to the reversal of a portion of our deferred tax asset valuation allowance.