Lease Commitments - Schedule of Other Information Related to Leases (Details) - USD ($) $ in Millions	12 Months Ended
Sep. 30, 2021	Sep. 30, 2020
Leases [Abstract]
Operating cash flows from operating leases	$ 50	$ 43
Operating cash flows from finance leases	8	4
Financing cash flows from finance leases	6	1
Leased assets obtained in exchange for operating lease obligations	83	49
Leased assets obtained in exchange for finance lease obligations	$ 118	$ 49

Amount of interest paid on finance lease liability.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 842
-SubTopic 20
-Section 50
-Paragraph 4
-Subparagraph (g)(1)
-URI http://asc.fasb.org/extlink&oid=121609121&loc=SL77918686-209980

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 842
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-Section 45
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Amount of cash outflow for principal payment on finance lease.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 842
-SubTopic 20
-Section 45
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-URI http://asc.fasb.org/extlink&oid=121603541&loc=SL77918643-209977

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
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Amount of cash outflow from operating lease, excluding payments to bring another asset to condition and location necessary for its intended use.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 842
-SubTopic 20
-Section 45
-Paragraph 5
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=121603541&loc=SL77918643-209977

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-Publisher FASB
-Name Accounting Standards Codification
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-SubTopic 20
-Section 50
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Amount of increase in right-of-use asset obtained in exchange for finance lease liability.

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-Publisher FASB
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Amount of increase in right-of-use asset obtained in exchange for operating lease liability.

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