Property, Plant and Equipment - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 28, 2019	Sep. 29, 2018	Sep. 28, 2019	Sep. 29, 2018	Dec. 31, 2018
Property, Plant and Equipment [Line Items]
Depreciation and amortization	$ 2,000	$ 1,400	$ 5,980	$ 3,046
Assets held-for-sale	8,900		8,900		$ 1,000
Cost of Goods Sold
Property, Plant and Equipment [Line Items]
Depreciation and amortization	1,400	1,000	4,200	2,400
Research and Development Expense
Property, Plant and Equipment [Line Items]
Depreciation and amortization	600	400	1,800	600
SG&A Expense
Property, Plant and Equipment [Line Items]
Depreciation and amortization	$ 17	$ 3	$ 39	$ 3