Summary of Significant Accounting Policies Improving the Presentation of Net Periodic Pension Cost (Details) - USD ($) $ in Millions	9 Months Ended
Jun. 30, 2020	Jun. 30, 2019
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
2017 Periodic Pension Cost Restatement	$ 0.0	$ (0.2)

Represents the quantification of the effect of adopting the new accounting standard or change in accounting principle expected by the entity to have a significant effect on the entity's financial statements.

No definition available.

Name:	us-gaap_NewAccountingPronouncementOrChangeInAccountingPrincipleEffectOfAdoptionQuantification
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration