Consolidated Statements of Operations - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Statement of Financial Position [Abstract]
Revenue	$ 1,029,353	$ 1,000,133	$ 890,960
Cost of goods sold	789,159	770,674	688,934
Gross profit	240,194	229,459	202,026
Operating expenses:
Selling, general and administrative expenses	196,194	195,006	183,444
Depreciation and amortization	17,472	17,723	13,664
Change in fair value of contingent consideration	(270)	(37,873)	(31,331)
Goodwill impairment charge	37,539	0	37,908
Intangible asset impairment charges	202	2,710	0
Restructuring and other charges	1,053	0	4,322
Income (loss) from operations	(11,996)	51,893	(5,981)
Other income (expense):
Interest income	69	57	76
Interest expense	(4,612)	(4,428)	(2,954)
Other, net	(3,135)	(747)	(357)
Total other expense	(7,678)	(5,118)	(3,235)
Income (loss) before taxes	(19,673)	46,775	(9,216)
Income tax expense (benefit)	12,665	2,313	(556)
Net income (loss)	$ (32,338)	$ 44,462	$ (8,660)
Basic earnings (loss) per share (in USD per share)	$ (0.61)	$ 0.85	$ (0.17)
Diluted earnings (loss) per share (in USD per share)	$ (0.61)	$ 0.84	$ (0.17)