General - Leases - Assets and Liabilities (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Components of lease assets and liabilities
Operating lease right-of-use assets	$ 20,832
Operating Lease, Right-of-Use Asset, Statement of Financial Position	us-gaap:OtherAssetsNoncurrent
Current operating lease liabilities	$ 23,959
Operating Lease, Liability, Current, Statement of Financial Position	us-gaap:AccruedLiabilitiesCurrent
Long-term operating lease liabilities	$ 9,661
Operating Lease, Liability, Noncurrent, Statement of Financial Position	us-gaap:DeferredCreditsAndOtherLiabilitiesNoncurrent
Total operating lease liabilities	$ 33,620
Operating Lease, Liability, Statement of Financial Position	us-gaap:AccruedLiabilitiesCurrent us-gaap:DeferredCreditsAndOtherLiabilitiesNoncurrent
Finance lease assets	$ 13,489
Finance Lease, Right-of-Use Asset, Statement of Financial Position	us-gaap:PropertyPlantAndEquipmentAndFinanceLeaseRightOfUseAssetAfterAccumulatedDepreciationAndAmortization
Current finance lease liabilities	$ 4,989
Finance Lease, Liability, Current, Statement of Financial Position	us-gaap:LongTermDebtAndCapitalLeaseObligationsCurrent
Long-term finance lease liabilities	$ 14,024
Finance Lease, Liability, Noncurrent, Statement of Financial Position	us-gaap:LongTermDebtAndCapitalLeaseObligations
Total finance lease liabilities	$ 19,013	$ 18,100
Total lease liabilities	$ 52,633