Leases - Costs Disclosure (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Leases
Weighted average remaining lease term	3 years		3 years		3 years
Lessee, Operating Lease, Existence of Option to Extend [true false]			true
Average discount rate (as a percent)	3.50%		3.50%		3.50%
Lease cost
Net operating lease costs	$ 415	$ 527	$ 1,334	$ 1,659
Minimum
Leases
Remaining lease term	1 year		1 year		1 year
Maximum
Leases
Remaining lease term	7 years		7 years		7 years
Lease extension term			5 years
Lease Term	12 months		12 months
Cost of revenues
Lease cost
Operating lease cost	$ 374	480	$ 1,214	1,520
Selling, general and administrative expense.
Lease cost
Operating lease cost	68	67	182	184
Interest and other income, net
Lease cost
Rental revenues	$ (27)	$ (20)	$ (62)	$ (45)