Consolidated Balance Sheet Parentheticals - USD ($) $ in Millions	Sep. 30, 2022	Sep. 30, 2021
Statement of Financial Position [Abstract]
Allowance for doubtful accounts, trade receivable	$ 3.8	$ 6.9
Preferred shares, par value (in usd per share)	$ 0.01	$ 0.01
Preferred shares, authorized (in shares)	10,000,000.0	10,000,000.0
Preferred shares, issued (in shares)	0	0
Preferred shares, outstanding (in shares)	0	0
Common shares, par value (in usd per share)	$ 0.01	$ 0.01
Common shares, authorized (in shares)	300,000,000	300,000,000.0
Common shares, issued (in shares)	65,251,989	65,251,989
Common shares, outstanding (in shares)	51,573,001	54,369,714
Treasury shares (in shares)	13,678,988	10,882,275

Amount of allowance for credit loss on accounts receivable, classified as current.

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