Leases - Future minimum lease payments (Details) $ in Thousands	Sep. 30, 2019 USD ($)
Operating leases
2019 (remainder of year)	$ 586
2020	2,394
2021	687
Total minimum lease payments	3,667
Total operating lease liability	3,667
Finance leases
2019 (excluding the six months ended June 30, 2019)	29
2020	116
2021	116
2022	84
2023 and thereafter	92
Total minimum lease payments	437
Imputed interest	(8)
Total finance lease liability	$ 429