Leases - Summary (Details) $ in Thousands	3 Months Ended	6 Months Ended
	Jun. 30, 2019 USD ($) lease	Jun. 30, 2019 USD ($) lease	Jan. 01, 2019 USD ($)	Dec. 31, 2018 USD ($)
Leases
Lease assets	$ 250	$ 250		$ 18
Lease liability	$ 249	$ 249
Number of finance leases | lease	0	0
Number of operating leases | lease	1	1
Operating lease expense	$ 48	$ 97
Operating lease expense information:
Cash paid for amounts included in measurement of lease liabilities	$ 35	$ 75
Weighted-average remaining lease term (years)	1 year 4 months 24 days	1 year 4 months 24 days
Weighted-average discount rate	21.20%	21.20%
ASU 2016-02
Leases
Lease assets			$ 300
Lease liability			$ 300