Leases - Supplemental balance sheet information (Details) $ in Thousands	Sep. 30, 2019 USD ($)
Leases
Operating lease right-of-use assets	$ 50,933
Operating lease asset location on balance sheet	us-gaap:OperatingLeaseRightOfUseAsset
Operating lease liabilities, current	$ 10,882
Operating lease liabilities current location on balance sheet	us-gaap:OperatingLeaseLiabilityCurrent
Operating lease liabilities, noncurrent	$ 44,535
Operating lease liabilities non current location on balance sheet	us-gaap:OperatingLeaseLiabilityNoncurrent
Total lease liabilities	$ 55,417
Minimum
Leases
Remaining lease terms, operating lease	1 year
Maximum
Leases
Remaining lease terms, operating lease	9 years