CONSOLIDATED STATEMENTS OF OPERATIONS (UNAUDITED) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Income Statement [Abstract]
Net sales	$ 138,512	$ 136,318	$ 392,983	$ 357,804
Cost of sales	111,640	117,510	322,793	311,056
Gross profit	26,872	18,808	70,190	46,748
Operating expenses:
Research, development and engineering expenses	6,366	7,708	18,695	20,691
Selling, general and administrative expenses	11,461	16,374	41,476	42,904
Amortization of intangible assets	910	1,321	2,729	3,687
Total operating expenses	18,737	25,403	62,900	67,282
Operating income (loss)	8,135	(6,595)	7,290	(20,534)
Other expense:
Interest expense	1,921	1,974	6,156	5,425
Loss from change in value and exercise of warrants	0	10,200	1,352	19,200
Other income, net	(25)	(68)	(526)	(257)
Total other expense	1,896	12,106	6,982	24,368
Income (loss) before income taxes	6,239	(18,701)	308	(44,902)
Income tax expense (benefit)	483	118	136	(74)
Net income (loss)	$ 5,756	$ (18,819)	$ 172	$ (44,828)
Weighted-average common shares outstanding:
Basic (in shares)	22,849	18,625	21,064	18,567
Diluted (in shares)	22,876	18,625	21,088	18,567
Earnings (loss) per common share:
Basic (in dollars per share)	$ 0.25	$ (1.01)	$ 0.01	$ (2.41)
Diluted (in dollars per share)	$ 0.25	$ (1.01)	$ 0.01	$ (2.41)