Income Taxes (Gross Unrecognized Tax Benefit) (Details) - USD ($) $ in Millions	12 Months Ended
Sep. 30, 2018	Sep. 30, 2017
Unrecognized Tax Benefits [Roll Forward]
Balance at beginning of year	$ 3.0	$ 2.8
Increases related to prior year positions	0.1	0.1
Increases related to current year positions	0.3	0.2
Decreases due to lapse in statute of limitations	(0.1)	(0.1)
Balance at end of year	$ 3.3	$ 3.0

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

No definition available.

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- Definition

Amount of unrecognized tax benefits.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 45
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- Definition

Amount of increase in unrecognized tax benefits resulting from tax positions that have been or will be taken in current period tax return.

+ References

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-Name Accounting Standards Codification
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- Definition

Amount of increase in unrecognized tax benefits resulting from tax positions taken in prior period tax returns.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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- Definition

Amount of decrease in unrecognized tax benefits resulting from lapses of applicable statutes of limitations.

+ References

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