Leases - Assets and Liabilities - Operating Leases (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Sep. 30, 2020
Assets and Liabilities, Lessee [Abstract]
Operating lease right-of-use assets	$ 49,650	$ 23,324
Operating Lease, Right-of-Use Asset, Statement of Financial Position	Other assets	Other assets
Accrued expenses and other current liabilities	$ 5,254	$ 3,972
Operating Lease, Liability, Current, Statement of Financial Position	Accrued expenses and other current liabilities	Accrued expenses and other current liabilities
Long-term operating lease liabilities	$ 45,088	$ 18,905
Total lease liability balance	$ 50,342	$ 22,877