Derivative Financial Instruments (Details) - USD ($) $ in Millions	12 Months Ended
Sep. 30, 2020	Sep. 30, 2019
Derivatives, Fair Value
Derivative, notional amount	$ 350.0
AOCI, cumulative changes in net gain (loss) from cash flow hedges, before tax	(9.4)
AOCI, cumulative changes in net gain (loss) from cash flow hedges, net of tax	(8.8)
Unrealized derivative net loss (gain) to be reclassified during next 12 months, net	2.3
Derivative liability, current	4.6	$ 0.0
Derivative liability, noncurrent	5.8
Derivative liability	10.4
Derivative loss (gain), net	2.8
Fair Value Adjustment
Derivatives, Fair Value
Derivative loss (gain), net	(0.2)
Net Cash Settlements
Derivatives, Fair Value
Derivative loss (gain), net	1.8
Reclassification from AOCI
Derivatives, Fair Value
Derivative loss (gain), net	$ 1.2

Accumulated Other Comprehensive Income, Cumulative Changes in Net Income (Loss) from Hedges, Before Tax

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Accumulated change, net of tax, in accumulated gains and losses from derivative instruments designated and qualifying as the effective portion of cash flow hedges. Includes an entity's share of an equity investee's Increase or Decrease in deferred hedging gains or losses.

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- Definition

Amount of realized and unrealized gain (loss) of derivative instruments not designated or qualifying as hedging instruments.

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Fair value, after the effects of master netting arrangements, of a financial liability or contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes liabilities not subject to a master netting arrangement and not elected to be offset.

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Fair value, after the effects of master netting arrangements, of a financial liability or contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset, expected to be settled within one year or normal operating cycle, if longer. Includes assets not subject to a master netting arrangement and not elected to be offset.

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Fair value, after the effects of master netting arrangements, of a financial liability or contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset, expected to be settled after one year or the normal operating cycle, if longer. Includes assets not subject to a master netting arrangement and not elected to be offset.

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Nominal or face amount used to calculate payment on derivative.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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No definition available.

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The estimated net amount of unrealized gains or losses on interest rate cash flow hedges as of the balance sheet date expected to be reclassified to earnings within the next twelve months.

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