Unusual Items - Schedule of Merger Costs (Details) $ in Millions	3 Months Ended
	Dec. 31, 2020 USD ($)
Unusual or Infrequent Item [Line Items]
Gain on legal matters and settlements	$ 7.7
Legal
Unusual or Infrequent Item [Line Items]
Gain on legal matters and settlements	3.9
Consulting and other professional costs
Unusual or Infrequent Item [Line Items]
Gain on legal matters and settlements	3.4
Internal labor
Unusual or Infrequent Item [Line Items]
Gain on legal matters and settlements	$ 0.4