Consolidated Statements of Operations - USD ($)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Statement of Financial Position [Abstract]
Revenue	$ 1,090,704,000	$ 1,029,353,000	$ 1,000,133,000
Cost of goods sold	827,156,000	789,159,000	770,674,000
Gross profit	263,548,000	240,194,000	229,459,000
Operating expenses:
Selling, general and administrative expenses	209,967,000	197,291,000	196,190,000
Depreciation and amortization	17,916,000	17,472,000	17,723,000
Change in fair value of contingent consideration	10,417,000	(270,000)	(37,873,000)
Goodwill impairment charge	0	37,539,000	0
Intangible asset impairment charges	70,000	202,000	2,710,000
Restructuring charges	5,615,000	1,053,000	0
Income (loss) from operations	19,563,000	(13,093,000)	50,709,000
Other income (expense):
Interest income	86,000	69,000	57,000
Interest expense	(4,171,000)	(4,612,000)	(4,428,000)
Other, net	(153,000)	(3,135,000)	(747,000)
Total other expense	(4,238,000)	(7,678,000)	(5,118,000)
Income (loss) before taxes	15,325,000	(20,771,000)	45,591,000
Income tax expense	10,955,000	12,292,000	1,855,000
Net income (loss)	$ 4,370,000	$ (33,063,000)	$ 43,736,000
Basic earnings (loss) per share (in USD per share)	$ 0.08	$ (0.63)	$ 0.84
Diluted earnings (loss) per share (in USD per share)	$ 0.08	$ (0.63)	$ 0.82