Operating Lease Commitments - Supplemental balance sheet information (Details) $ in Thousands	Dec. 31, 2019 USD ($)
Assets [Abstract]
Operating lease right-of-use asset	$ 22,027
Financial position	us-gaap:OperatingLeaseRightOfUseAsset
Liabilities [Abstract]
Operating lease current liability, included in other current liabilities	$ 4,556
Financial position	us-gaap:OtherLiabilitiesCurrent
Long-term lease liabilities	$ 17,971
Financial position	us-gaap:OperatingLeaseLiabilityNoncurrent
Total lease liabilities	$ 22,527