Selected Quarterly Financial Data (Unaudited) - CONDENSED CONSOLIDATED BALANCE SHEETS (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Jan. 01, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016
Current assets:
Cash and cash equivalents	$ 54	$ 2,014	$ 2	$ 0		$ 0	$ 0	$ 0	$ 342
Accounts receivable, net	86,471	71,639	70,324	58,870		68,660	60,811	56,673	64,305
Income tax receivable	973	1,018	1,018	1,018		1,018	841	1,996	6,829
Inventories, net	105,614	112,392	95,957	91,689	$ 81,565	86,724	113,074	103,335	97,286
Prepaid expenses and other current assets	22,917	26,905	26,644	20,555	20,525	14,359	14,536	12,453	15,291
Total current assets	216,029	213,968	193,945	172,132		170,761	189,262	174,457	184,053
Property, plant and equipment, net	24,266	24,536	24,931	18,474		18,960	18,974	19,050	19,230
Intangible assets, net	17,010	20,534	21,854	23,175		21,491	22,401	23,610	24,819
Goodwill	29,835	29,835	29,835	29,835		29,835	29,835	29,835	29,835
Other noncurrent assets	2,742	3,818	3,552	4,957		5,972	6,035	4,518	5,053
TOTAL ASSETS	289,882	292,691	274,117	248,573		247,019	266,507	251,470	262,990
Current liabilities:
Accounts payable	85,218	88,798	64,422	55,221		51,225	54,195	55,610	67,167
Contingent consideration							20	29	30
Revolving line of credit	54,613	52,491	54,334	36,662		37,055	41,332	25,263	16,887
Warrant liability	35,100	43,900	33,700	0		0
Other accrued liabilities	45,700	44,762	41,884	38,697	33,626	34,332	37,295	30,110	28,809
Total current liabilities	220,631	229,951	194,340	130,580		122,612	132,842	111,012	112,893
Deferred income taxes	647	616	495	427		703	1,210	1,066	933
Warrant liability	0	0	0	27,200		24,700	23,200	21,500	20,700
Long-term debt	54,712	54,781	54,604	54,575		54,439	54,306	54,168	54,046
Other noncurrent liabilities	32,470	16,612	15,753	15,311		12,393	17,410	17,707	19,753
TOTAL LIABILITIES	308,460	301,960	265,192	228,093		214,847	228,968	205,453	208,325
MEZZANINE EQUITY / STOCKHOLDERS’ EQUITY
Series B convertible preferred stock, net of issuance costs	62,500						31,410	27,807	24,617
Preferred stock	0	0	0	0		0	0	0	0
Common stock	19	19	19	19		19	14	14	14
Additional paid-in capital	126,412	125,938	125,272	124,981		123,838	91,737	96,543	100,686
Accumulated deficit	(135,160)	(125,262)	(106,443)	(94,638)	$ (80,434)	(82,147)	(76,018)	(66,817)	(59,070)
Treasury stock, at cost	(9,849)	(9,964)	(9,923)	(9,882)		(9,538)	(9,604)	(11,530)	(11,582)
TOTAL STOCKHOLDERS’ (DEFICIT) EQUITY	(18,578)	(9,269)	8,925	20,480		32,172	6,129	18,210	30,048	$ 40,660
TOTAL LIABILITIES AND STOCKHOLDERS’ (DEFICIT) EQUITY	$ 289,882	$ 292,691	$ 274,117	$ 248,573		$ 247,019	$ 266,507	$ 251,470	$ 262,990