Leases (Details) - USD ($)	3 Months Ended	6 Months Ended
	Mar. 31, 2020	Mar. 31, 2020	Sep. 30, 2019
Leases [Abstract]
Operating right of use assets	$ 31,600,000	$ 31,600,000	$ 0
Operating Lease, Cost	$ 3,500,000	$ 7,000,000
Operating Lease, Weighted Average Remaining Lease Term	4 years 2 months 16 days	4 years 2 months 16 days
Operating Lease, Weighted Average Discount Rate, Percent	5.10%	5.10%
Operating Lease, Payments	$ 2,800,000	$ 5,500,000
Right-of-Use Asset Obtained in Exchange for Operating Lease Liability	400,000	35,000,000
Operating lease liabilities	$ 34,200,000	$ 34,200,000	$ 0