Related Party Transactions (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
Mar. 31, 2020	Mar. 31, 2019	Mar. 31, 2020	Mar. 31, 2019	Sep. 30, 2019
Related Party Transactions [Abstract]
Net sales to related parties	$ 96	$ 88	$ 195	$ 180
Purchases from related parties	132	$ 177	309	$ 350
Accounts receivable due from related parties	66		66		$ 73
Accounts payable due to related parties	$ 93		$ 93		$ 137

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

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