Leases - Balance sheet information (Details) $ in Thousands	Dec. 31, 2019 USD ($)
Operating lease
Operating lease right-of-use assets	$ 12,645
Operating lease liabilities, current	$ 2,772
Operating Lease, Liability, Current, Statement of Financial Position	leaf:AccruedAndOtherLiabilitiesCurrent
Operating lease liabilities, noncurrent	$ 10,863
Operating Lease, Liability, Noncurrent, Statement of Financial Position	us-gaap:AccruedAndOtherLiabilitiesCurrent us-gaap:OperatingLeaseLiabilityNoncurrent
Total operating lease liabilities	$ 13,635
Weighted average remaining lease term, Operating lease	4 years
Weighted average discount rate, Operating lease	9.00%