Commitments and Contingencies - Cash flow information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Commitments and Contingencies.
Operating cash flows from operating leases	$ (167)
Operating cash flows from operating leases, pre-adoption		$ (1,393)
Financing cash flows from finance leases	$ (12)
Financing cash flows from finance leases, pre-adoption		$ (14)