Leases - Costs Disclosure (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2019 USD ($)
Leases
Weighted average remaining lease term	3 years
Lessee, Operating Lease, Existence of Option to Extend [true false]	true
Average discount rate (as a percent)	3.50%
Lease cost
Total lease cost	$ 527
Minimum
Leases
Remaining lease term	0 years
Maximum
Leases
Remaining lease term	6 years
Lease extension term	5 years
Lease Term	12 months
Cost of revenues
Lease cost
Operating lease cost	$ 486
Selling, general and administrative expense.
Lease cost
Operating lease cost	53
Other (income) expense, net
Lease cost
Rental revenues	$ (12)