Leases (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2020 USD ($) ft²	Dec. 31, 2019 USD ($)	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	2,810	$ 2,938
Operating lease liability	$ 2,905
Lease, Practical Expedients, Package [true false]	true
ASU 2016-02
Leases
Operating lease right-of-use assets			$ 1,100
Operating lease liability			$ 1,100