Fair Value - Summary of Accounts Receivable Sales Agreement (Details) - USD ($) $ in Millions	9 Months Ended
Jun. 30, 2022	Jun. 30, 2021
Fair Value Disclosures [Abstract]
Receivables sold to the financial institutions and derecognized	$ (2,200.7)	$ (2,011.9)
Receivables collected by financial institutions	2,113.3	1,939.6
Cash proceeds from financial institutions	$ 87.4	$ 72.3

Represents the initial fair value recorded for assets received on transfer of financial assets in a securitization, asset-backed financing arrangement, or a similar transfer which transaction is recognized as a sale of the transferred financial assets.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 860
-SubTopic 20
-Section 50
-Paragraph 3
-Subparagraph (bb)(3)
-URI http://asc.fasb.org/extlink&oid=121570589&loc=d3e107207-111719

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 860
-SubTopic 20
-Section 50
-Paragraph 3
-Subparagraph (bb)(2)
-URI http://asc.fasb.org/extlink&oid=121570589&loc=d3e107207-111719

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 860
-SubTopic 20
-Section 50
-Paragraph 3
-Subparagraph (b)(2)(i)
-URI http://asc.fasb.org/extlink&oid=121570589&loc=d3e107207-111719

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 860
-SubTopic 20
-Section 50
-Paragraph 3
-Subparagraph (bb)(1)
-URI http://asc.fasb.org/extlink&oid=121570589&loc=d3e107207-111719

Name:	us-gaap_TransfersOfFinancialAssetsAccountedForAsSaleInitialFairValueOfAssetsObtainedAsProceeds
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant