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Nonconsolidated Partially-Owned Affiliates - (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
	Mar. 31, 2022	Mar. 31, 2022	Sep. 30, 2021
Schedule of Equity Method Investments [Line Items]
Investments in partially-owned affiliates	$ 376	$ 376	$ 335
KEIPER
Schedule of Equity Method Investments [Line Items]
Estimated possible claim amount	17	17
Affiliate Of Yangeng \| KEIPER
Schedule of Equity Method Investments [Line Items]
Estimated possible claim amount	46	46
South Africa
Schedule of Equity Method Investments [Line Items]
Proceeds from sale of equity method investments	2
Non-cash impairment on investment	$ 3	$ 6