Inventories - Reserve Rollforward (Details) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2020	Dec. 31, 2019
Inventory, Reserve [Roll Forward]
Beginning balance	$ (3,645)	$ (4,212)
Accrual	(75)	(814)
Reduction due to sold inventory	288	845
Write-off for disposed inventory	17	536
Reserves for excess, obsolete, and slow-moving inventories	$ (3,415)	$ (3,645)