CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Income Statement [Abstract]
Net sales	$ 417,639	$ 546,076
Cost of sales	359,191	446,188
Gross profit	58,448	99,888
Operating expenses:
Research, development and engineering expenses	25,375	24,932
Selling, general and administrative expenses	51,744	54,115
Amortization of intangible assets	3,053	3,638
Total operating expenses	80,172	82,685
Operating (loss) income	(21,724)	17,203
Other expense, net:
Interest expense	5,714	7,871
Loss from change in value and exercise of warrants	0	1,352
Loss on debt extinguishment and modifications	497	0
Other income, net	(1,240)	(677)
Total other expense, net	4,971	8,546
(Loss) income before income taxes	(26,695)	8,657
Income tax (benefit) expense	(3,713)	409
Net (loss) income	$ (22,982)	$ 8,248
Weighted-average common shares outstanding:
Basic (in shares)	22,872	21,512
Diluted (in shares)	22,872	21,530
(Loss) earnings per common share:
Basic (in dollars per share)	$ (1.00)	$ 0.38
Diluted (in dollars per share)	$ (1.00)	$ 0.38