Deferred Revenue and Remaining Performance Obligations (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020
Disaggregation of Revenue [Line Items]
Deferred revenue	$ 469		$ 469		$ 376
Revenues recognized included in contract liabilities balances	100	$ 100	300	$ 200
Revenue expected to be recognized from remaining performance obligations	10,500		$ 10,500
Contact period			These agreements have between two and four year terms and revenue is recognized as product is shipped, typically on a straight-line basis. The remaining balance relates to executed service contracts that begin as warranty periods expire. These service contracts typically provide for four-year terms and revenue is recognized on a straight-line basis.
Products and services not yet delivered
Disaggregation of Revenue [Line Items]
Deferred revenue	$ 469		$ 469		$ 376