Leases - Assets and Liabilities (Details) $ in Thousands	Sep. 30, 2019 USD ($)
Assets and liabilities
Operating lease assets	$ 46,755
Operating Lease, Right-of-Use Asset, Statement of Financial Position [Extensible List]	Operating lease assets
Operating lease liabilities, current	$ 6,833
Operating Lease, Liability, Current, Statement of Financial Position [Extensible List]	Other Accrued Liabilities, Current
Operating lease liabilities	$ 48,620
Operating Lease, Liability, Noncurrent, Statement of Financial Position [Extensible List]	Operating lease liabilities
Total operating lease liabilities	$ 55,453