Leases - Lease Assets and Liabilities (Details) $ in Thousands	Sep. 30, 2019 USD ($)
Operating lease assets and liabilities recorded on the balance sheet
Right-of-use assets - operating leases	$ 48,237
Financial position	us-gaap:OtherAssetsNoncurrent
Current portion of lease liabilities - operating leases	$ 2,869
Financial position	us-gaap:OtherLiabilitiesCurrent
Lease liabilities - operating leases	$ 52,285
Financial position	us-gaap:OtherLiabilitiesNoncurrent
Total operating lease liabilities	$ 55,154
Weighted average remaining lease term (in years)	13 years 7 months 6 days