Leases - Costs Disclosure (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 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	$ 504	$ 596	$ 919	$ 1,122
Minimum
Leases
Remaining lease term			1 year		1 year
Maximum
Leases
Remaining lease term			7 years		7 years
Lease extension term			5 years
Lease Term	12 months		12 months
Cost of revenues
Lease cost
Operating lease cost	$ 455	555	$ 840	1,040
Selling, general and administrative expense.
Lease cost
Operating lease cost	57	54	114	107
Interest and other income, net
Lease cost
Rental revenues	$ (8)	$ (13)	$ (35)	$ (25)