Commitments and Contingencies - Leases (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2019 USD ($) ft²	Jan. 01, 2019 USD ($)
Leases
Area of leased property (in square feet) | ft²	19,467
Operating lease, option to extend	true
Operating lease, extension term	3 years
Variable lease payments	$ 0
Residual value guarantee	0
Operating lease right-of-use assets	2,938
Operating lease liability	$ 3,014
Lease, Practical Expedients, Package [true false]	true
ASU 2016-02
Leases
Operating lease right-of-use assets		$ 1,086
Operating lease liability		1,100
Adjustment. | ASU 2016-02
Leases
Operating lease right-of-use assets	$ 1,100	$ 1,086
Operating lease liability	$ 1,100