CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Income Statement [Abstract]
Net sales	$ 546,076	$ 496,038
Cost of sales	446,188	437,269
Gross profit	99,888	58,769
Operating expenses:
Research, development and engineering expenses	24,932	28,601
Selling, general and administrative expenses	54,114	59,631
Asset impairment charges	1	2,234
Amortization of intangible assets	3,638	5,008
Total operating expenses	82,685	95,474
Operating income (loss)	17,203	(36,705)
Other expense:
Interest expense	7,871	7,628
Loss from change in value and exercise of warrants	1,352	10,400
Other income, net	(677)	(176)
Total other expense	8,546	17,852
Income (loss) before income taxes	8,657	(54,557)
Income tax expense	409	169
Net income (loss)	$ 8,248	$ (54,726)
Weighted-average common shares outstanding:
Basic (in shares)	21,512	18,585
Diluted (in shares)	21,530	18,585
Earnings (loss) per common share:
Basic (in dollars per share)	$ 0.38	$ (2.94)
Diluted (in dollars per share)	$ 0.38	$ (2.94)