Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	3 Months Ended								6 Months Ended		9 Months Ended		12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Jun. 30, 2019	Jun. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Statement of Financial Position [Abstract]
Revenue	$ 319,074	$ 287,688	$ 283,861	$ 267,211	$ 293,977	$ 270,844	$ 281,988	$ 274,297	$ 551,072	$ 556,285	$ 838,760	$ 827,129	$ 1,157,834	$ 1,121,106	$ 1,138,370
Cost of goods sold		218,193	215,463	205,201	234,911	206,877	217,047	208,458	420,664	425,505	638,857	632,382	895,825	867,293	862,862
Gross profit	62,106	69,495	68,398	62,010	59,066	63,967	64,941	65,839	130,408	130,780	199,903	194,747	262,009	253,813	275,508
Operating expenses:
Selling, general and administrative expenses		59,751	57,404	55,830	62,124	56,167	59,050	61,196	113,235	120,246	172,986	176,413	222,721	238,537	227,895
Depreciation and amortization													12,328	12,988	13,390
Change in fair value of contingent consideration													0	0	677
Goodwill impairment					18,400	27,900							0	46,319	0
Intangible and other asset impairments						13,800							0	18,121	0
Restructuring charges		2,892									10,524		15,918	6,031	0
Income (loss) from operations	3,588	3,762	4,063	(371)	(28,232)	(43,312)	2,377	984	3,692	3,361	7,454	(39,951)	11,042	(68,183)	33,546
Other income (expense):
Interest income													366	218	97
Interest expense													(14,097)	(7,749)	(4,729)
Other, net		(1,735)	279	(440)					(161)		(1,896)		(3,686)	(1,616)	(1,788)
Total other expense		(6,074)	(2,103)	(3,087)					(5,191)		(11,265)		(17,417)	(9,147)	(6,420)
(Loss) income before income taxes		(2,312)	1,960	(3,458)	(30,926)	(45,363)	326	(1,368)	(1,499)	(1,042)	(3,811)	(46,404)	(6,375)	(77,330)	27,126
Provision (benefit) for income tax		(1,250)	2,468	(1,414)	(1,536)	(243)	625	506	1,053	1,131	(197)	889	3,700	(647)	11,257
Net (loss) income	$ (6,461)	$ (1,062)	$ (508)	$ (2,044)	$ (29,390)	$ (45,120)	$ (299)	$ (1,874)	$ (2,552)	$ (2,173)	$ (3,614)	$ (47,293)	$ (10,075)	$ (76,683)	$ 15,869
Basic (loss) earnings per share (in USD per share)		$ (0.02)	$ (0.01)	$ (0.04)	$ (0.57)	$ (0.87)	$ (0.01)	$ (0.03)	$ (0.05)	$ (0.04)	$ (0.07)	$ (0.90)	$ (0.19)	$ (1.47)	$ 0.29
Diluted (loss) earnings per share (in USD per share)		$ (0.02)	$ (0.01)	$ (0.04)	$ (0.57)	$ (0.87)	$ (0.01)	$ (0.03)	$ (0.05)	$ (0.04)	$ (0.07)	$ (0.90)	$ (0.19)	$ (1.47)	$ 0.29
Weighted average shares outstanding - basic (in shares)													53,293	52,230	53,851
Weighted average shares outstanding - diluted (in shares)													53,293	52,230	54,944