Commitments and Contingencies - Leases (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Operating leases rental expenses, after adoption of Topic 842
Lease costs	$ 2,612
Less: income from subleases	0
Net lease costs	2,612
Operating leases rental expenses, before adoption of Topic 842
Lease costs		$ 2,829	$ 2,614
Less: income from subleases		(347)	(418)
Net lease costs		$ 2,482	$ 2,196
Future lease obligations under our operating leases
2020	1,792
2021	970
2022	749
2023	367
2024	223
Thereafter	9
Total lease payments	4,110
Less: imputed interest	(194)
Operating lease liability	$ 3,916