Debt and lease liabilities (Operating Lease Liabilities) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Lessee, Lease, Description [Line Items]
Discount rate	5.50%		5.50%
Weighted average lease term	3 years 6 months 7 days		3 years 6 months 7 days
Operating rental expenses	$ 201	$ 89	$ 385	$ 178
Monthly Rental Payments | Related Party
Lessee, Lease, Description [Line Items]
Rental payments			20
Total rental payments	$ 61	$ 61	$ 121	$ 121