Basis of Presentation and Summary of Significant Accounting Policies - Disaggregation of Revenue (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Revenue from External Customer [Line Items]
Net sales	$ 2,749	$ 5,964	$ 7,460	$ 13,082
Commercial
Revenue from External Customer [Line Items]
Net sales	1,522	1,456	3,513	4,250
MMM products
Revenue from External Customer [Line Items]
Net sales	$ 1,227	$ 4,508	$ 3,947	$ 8,832