Quarterly Result of Operations (Unaudited) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Quarterly Financial Information Disclosure [Abstract]
Sales	$ 104,141	$ 90,516	$ 93,491	$ 93,617	$ 112,844	$ 99,705	$ 98,244	$ 92,834	$ 381,765	$ 403,627	$ 360,917
Gross profit	43,601	50,772	50,741	53,018	62,841	50,612	55,994	52,106	198,132	221,553	198,682
Net income	$ (49,695)	$ (6,199)	$ (6,405)	$ 152	$ 5,758	$ (2,488)	$ 1,205	$ 455	(62,147)	4,930	(14,516)
INCOME TAX EXPENSE (BENEFIT)									$ 1,133	$ (372)	$ 20,343
Net income (loss) per share:
Basic earnings (loss) per share (in dollars per share)	$ (2.85)	$ (0.36)	$ (0.37)	$ 0.01	$ 0.33	$ (0.15)	$ 0.07	$ 0.03	$ (3.58)	$ 0.29	$ (0.87)
Diluted EPS (in dollars per share)	$ (2.85)	$ (0.36)	$ (0.37)	$ 0.01	$ 0.33	$ (0.15)	$ 0.07	$ 0.03	$ (3.58)	$ 0.29	$ (0.87)
Disaggregation of Revenue [Line Items]
Provision for excess and obsolete inventory	$ 15,100					$ 4,700			$ 16,886	$ 5,757	$ 1,734
Assets impairment charges	35,200								$ 35,213	$ 0	$ 0
Change in tax rate, provisional income tax expense (benefit)					$ (1,000)
Goodwill
Disaggregation of Revenue [Line Items]
Assets impairment charges	21,200
Acquired Intangible Assets
Disaggregation of Revenue [Line Items]
Assets impairment charges	10,500
Intangible Assets - Capitalized Patents
Disaggregation of Revenue [Line Items]
Assets impairment charges	1,400
Other Asset Write Downs
Disaggregation of Revenue [Line Items]
Assets impairment charges	$ 2,100
Government Contract
Disaggregation of Revenue [Line Items]
Charges to income from price adjustment clauses			$ 5,800		$ 4,800