CONSOLIDATED STATEMENTS OF EARNINGS AND COMPREHENSIVE INCOME (Parenthetical) - USD ($) $ in Millions	12 Months Ended
Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2018
Income Statement [Abstract]
Income tax expense, discontinued operations	$ 1.2	$ 4.0
Pension activity, tax	3.5	(12.1)	$ 6.3
Deferred (loss)/gain on hedging activity, net of tax of ($1.5) in 2020, ($3.1) in 2019, and $4.4 in 2018	$ (1.5)	$ (3.1)	$ 4.4

Amount of tax expense (benefit) related to a discontinued operation. Includes, but is not limited to, tax expense (benefit) related to income (loss) from operations during the phase-out period, tax expense (benefit) related to gain (loss) on disposal, tax expense (benefit) related to gain (loss) for reversal of write-down (write-down) to fair value, less cost to sell, and tax expense (benefit) related to adjustments of a prior period gain (loss) on disposal.

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