Leases - Supplemental Balance Sheet Information (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2018	Jun. 30, 2019
Leases
Operating lease ROU assets			$ 27,235
Financial position			us-gaap:OtherAssetsNoncurrent
Operating lease liabilities - current			$ 11,831
Financial position			us-gaap:OtherLiabilitiesCurrent
Operating lease liabilities - noncurrent			$ 16,478
Financial position			us-gaap:OtherLiabilitiesNoncurrent
Total Operating lease liabilities			$ 28,309
Financing Lease ROU assets			$ 394
Financial position			Property, Plant and Equipment, Net
Finance lease liabilities - current			$ 266
Financial position			us-gaap:OtherLiabilitiesCurrent
Finance lease liabilities - noncurrent			$ 141
Financial position			us-gaap:OtherLiabilitiesNoncurrent
Finance lease liabilities			$ 407
Weighted average remaining lease term - Operating leases			4 years
Weighted average remaining lease term - Financing leases			2 years
Weighted average discount rate - Operating leases			4.33%
Weighted average discount rate - Financing leases			6.00%
Rent expense before adoption	$ 5,800	$ 11,800
Finance lease assets
Leases
Property and equipment, gross			$ 1,211
Accumulated depreciation			$ (817)