Significant Accounting Policies (Details) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2018
Trade Accounts Receivable and Accounts Receivable, Other
Allowance for Doubtful Accounts	$ 1.9	$ 1.7
Selling, general and administrative expenses
Property Plant and Equipment
Depreciation expense	$ 95.5	$ 96.1	$ 97.2