Income Taxes - Reconciliation of Income Tax Expense (Benefit) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Tax expense at statutory rate	$ (12,812)	$ 956	$ 1,981
State income taxes, net of federal benefit	(1,564)	(13)	81
Foreign tax rate difference	(1,954)	(1,003)	(2,057)
Research and development credit	(753)	(919)	(1,037)
Change in valuation allowance	8,485	464	678
Equity based compensation	(25)	(390)	33
Manufacturing credit	0	0	(191)
Permanent impact of non-deductible cost	1,550	727	766
Provision to return adjustments & deferred adjustments	356	(654)	777
Impact of the U.S. Tax Cuts and Jobs Act of 2017	0	0	17,340
Change in enacted tax rates	359	58	2,015
Global intangible low-taxed income (“GILTI”)	1,795	402	0
Intangible & goodwill impairment	4,999	0	0
Other	697	0	(43)
Income tax expense (benefit)	$ 1,133	$ (372)	$ 20,343