Selected Quarterly Financial Data (Unaudited) - Effect of Restatement on Consolidated Balance Sheets (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Current assets:
Cash and cash equivalents	$ 0	$ 0	$ 0	$ 342	$ 2,292	$ 1,610	$ 435	$ 1,495	$ 8,445	$ 6,561	$ 6,306
Accounts receivable, net	68,660	60,811	56,673	64,305	60,336	53,364	57,884	45,384	70,532	76,266
Income tax receivable	1,018	841	1,996	6,829	7,127	5,737	3,384	1,723	5,265	0
Inventories, net	86,724	113,074	103,335	97,286	100,548	111,133	115,062	139,519	162,095	106,250
Prepaid expenses and other current assets	14,359	14,536	12,453	15,291	13,644	5,146	4,026	4,132	2,703	4,840
Total current assets	170,761	189,262	174,457	184,053	183,947	176,990	180,791	192,253	249,040	202,469
Property, plant and equipment, net	18,960	18,974	19,050	19,230	20,127	20,257	20,386	20,662	22,809	17,954
Intangible assets, net	21,491	22,401	23,610	24,819	26,029	27,459	28,888	30,316	31,745	21,192
Goodwill	29,835	29,835	29,835	29,835	29,835	29,835	29,835	29,835	29,835	23,414	0
Deferred income taxes	0				0	0	0	19,285	17,657	13
Other noncurrent assets	5,972	6,035	4,518	5,053	4,681	2,821	2,621	2,664	2,751	1,903
TOTAL ASSETS	247,019	266,507	251,470	262,990	264,619	257,362	262,521	295,015	353,837	266,945
Current liabilities:
Accounts payable	51,225	54,195	55,610	67,167	53,588	45,764	49,729	43,160	79,823	67,713
Contingent consideration	12	20	29	30	26	88	100	5,481	8,275	0
Other accrued liabilities	38,362	41,393	35,379	35,234	32,507	22,405	19,182	17,929	17,846	18,182
Total current liabilities	126,654	136,940	116,281	119,318	99,645	85,626	83,049	66,570	105,944	87,562
Long-term obligations
Revolving line of credit	0				0	0	0	80,568	97,299	78,030
Warrants	24,700	23,200	21,500	20,700	0	0	0	226	1,482	11,036
Long-term debt, less current maturities, net	54,439	54,305	54,168	54,045	110,392	111,517	110,929	53,799	53,805	2,361
Other noncurrent liabilities	8,351	13,312	12,438	13,328	13,458	12,730	12,833	11,952	10,434	1,473
TOTAL LIABILITIES	214,847	228,967	205,453	208,324	223,959	210,395	207,184	213,115	268,964	180,462
STOCKHOLDERS’ EQUITY
Preferred stock	0	0	0	0	0	0	0	0	0	0
Common stock - $0.001 par value. Authorized: 50,000,000 shares. Issued and Outstanding: 11,583,831 and 11,562,209 shares, at December 31, 2015 and 2014	19	14	14	14	12	12	12	11	11	11
Additional paid-in capital	123,838	91,737	96,543	100,686	86,764	86,408	86,043	83,729	83,377	81,746
Retained earnings	(82,147)	(76,018)	(66,817)	(59,070)	(34,535)	(27,895)	(19,180)	9,612	12,937	15,828
Treasury stock, at cost	(9,538)	(9,604)	(11,530)	(11,582)	(11,581)	(11,558)	(11,537)	(11,452)	(11,452)	(11,102)
TOTAL STOCKHOLDERS’ EQUITY	32,172	6,129	18,210	30,048	40,660	46,967	55,337	81,900	84,873	86,483	47,607
TOTAL LIABILITIES AND STOCKHOLDERS’ EQUITY	$ 247,019	$ 266,507	$ 251,470	$ 262,990	$ 264,619	$ 257,362	$ 262,521	295,015	353,837	266,945
Previously Reported
Current assets:
Cash and cash equivalents								1,495	8,445	6,561
Accounts receivable, net								63,163	104,365	81,740
Income tax receivable								0	5,230
Inventories, net								120,735	130,347	93,903
Prepaid expenses and other current assets								9,496	4,288	4,801
Total current assets								194,889	252,675	191,003
Property, plant and equipment, net								24,289	26,001	20,892
Intangible assets, net								30,316	31,745	21,392
Goodwill								41,466	41,466	23,546
Deferred income taxes								819	819	0
Other noncurrent assets								7,181	7,230	5,804
TOTAL ASSETS								298,960	359,936	262,637
Current liabilities:
Accounts payable								41,491	76,078	60,877
Contingent consideration								0	8,788
Other accrued liabilities								19,692	14,396	13,504
Total current liabilities								61,183	99,262	76,048
Long-term obligations
Revolving line of credit								80,568	97,299	78,030
Warrants								226	1,482	11,036
Long-term debt, less current maturities, net								53,946	53,820	2,361
Other noncurrent liabilities								1,670	1,776	1,122
TOTAL LIABILITIES								197,593	253,639	171,838
STOCKHOLDERS’ EQUITY
Preferred stock								0	0	0
Common stock - $0.001 par value. Authorized: 50,000,000 shares. Issued and Outstanding: 11,583,831 and 11,562,209 shares, at December 31, 2015 and 2014								12	12	12
Additional paid-in capital								75,500	75,179	73,959
Retained earnings								30,105	35,356	21,078
Treasury stock, at cost								(4,250)	(4,250)	(4,250)
TOTAL STOCKHOLDERS’ EQUITY								101,367	106,297	90,799	50,421
TOTAL LIABILITIES AND STOCKHOLDERS’ EQUITY								298,960	359,936	262,637
Restatement Adjustments and Reclassifications
Current assets:
Cash and cash equivalents								0	0	0
Accounts receivable, net								(17,779)	(33,833)	(5,474)
Income tax receivable								1,723	35
Inventories, net								18,784	31,748	12,347
Prepaid expenses and other current assets								(5,364)	(1,585)	39
Total current assets								(2,636)	(3,635)	11,466
Property, plant and equipment, net								(3,627)	(3,192)	(2,938)
Intangible assets, net								0	0	(200)
Goodwill								(11,631)	(11,631)	(132)
Deferred income taxes								18,466	16,838	13
Other noncurrent assets								(4,517)	(4,479)	(3,901)
TOTAL ASSETS								(3,945)	(6,099)	4,308
Current liabilities:
Accounts payable								1,669	3,745	6,836
Contingent consideration								5,481	(513)
Other accrued liabilities								(1,763)	3,450	4,678
Total current liabilities								5,387	6,682	11,514
Long-term obligations
Revolving line of credit								0	0	0
Warrants								0	0	0
Long-term debt, less current maturities, net								(147)	(15)	0
Other noncurrent liabilities								10,282	8,658	351
TOTAL LIABILITIES								15,522	15,325	8,624
STOCKHOLDERS’ EQUITY
Preferred stock								0	0	0
Common stock - $0.001 par value. Authorized: 50,000,000 shares. Issued and Outstanding: 11,583,831 and 11,562,209 shares, at December 31, 2015 and 2014								(1)	(1)	(1)
Additional paid-in capital								8,229	8,198	7,787
Retained earnings								(20,493)	(22,419)	(5,250)
Treasury stock, at cost								(7,202)	(7,202)	(6,852)
TOTAL STOCKHOLDERS’ EQUITY								(19,467)	(21,424)	(4,316)	$ (2,891)
TOTAL LIABILITIES AND STOCKHOLDERS’ EQUITY								$ (3,945)	$ (6,099)	$ 4,308