Related Party Transactions (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
Mar. 31, 2021	Mar. 31, 2020	Mar. 31, 2021	Mar. 31, 2020	Sep. 30, 2020
Related Party Transactions [Abstract]
Net sales to related parties	$ 69	$ 96	$ 139	$ 195
Purchases from related parties	148	$ 132	294	$ 309
Accounts receivable due from related parties	47		47		$ 49
Accounts payable due to related parties	$ 79		$ 79		$ 105

For an unclassified balance sheet, amount of receivables arising from transactions with related parties.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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Name:	us-gaap_AccountsReceivableRelatedParties
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant