Segment and Geographic Information - Schedule of Revenue by Type (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Entity Wide Information Revenue From External Customer [Line Items]
Total revenue	$ 20,680	$ 26,154	$ 52,184	$ 78,552
Lease Revenue
Entity Wide Information Revenue From External Customer [Line Items]
Total revenue	9,431	16,427	23,709	48,812
System Revenue
Entity Wide Information Revenue From External Customer [Line Items]
Total revenue	7,503	7,105	17,758	21,188
Product Revenue
Entity Wide Information Revenue From External Customer [Line Items]
Total revenue	2,631	1,167	7,136	4,117
Service Revenue
Entity Wide Information Revenue From External Customer [Line Items]
Total revenue	$ 1,115	$ 1,455	$ 3,581	$ 4,435