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Long-Term Debt (Details) - USD ($) $ in Millions	12 Months Ended
Long-Term Debt (Details) - USD ($) $ in Millions	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2019
Debt Instrument [Line Items]
Long-term debt	$ 6,331	$ 6,648
Less: Current maturities	538	322
Total, net	5,793	6,326
Long-term debt maturing during year two	505
Long-term debt maturing during year three	592
Long-term debt maturing during year four	497
Long-term debt maturing during year five	577
Interest paid related to long-term debt	156	163	$ 195
4.875% notes due October 2019 [Member]
Debt Instrument [Line Items]
Repayments of Debt		$ 500
Notes interest rate, percentage		4.875%
4.25% notes due November 2020 [Member]
Debt Instrument [Line Items]
Long-term debt	0	$ 300
Repayments of Debt	$ 300
Notes interest rate, percentage	4.25%
2.625% notes due December 2021 [Member]
Debt Instrument [Line Items]
Long-term debt	$ 500	500
2.625% notes due February 2023 [Member]
Debt Instrument [Line Items]
Long-term debt	500	500
0.375% notes due May 2024 [Member]
Debt Instrument [Line Items]
Long-term debt	579	586
3.15% notes Due June 2025 [Member]
Debt Instrument [Line Items]
Long-term debt	500	500
1.25% notes due October 2025 [Member]
Debt Instrument [Line Items]
Long-term debt	579	586
0.875% Notes Due October 2026 [Member]
Debt Instrument [Line Items]
Long-term debt	750	$ 750
Notes interest rate, percentage		0.875%
Proceeds from issuance of debt		$ 750
1.8% Notes Due October 2027 [Member]
Debt Instrument [Line Items]
Long-term debt	500	$ 500
Notes interest rate, percentage		1.80%
Proceeds from issuance of debt		$ 500
2.0% notes due October 2029 [Member]
Debt Instrument [Line Items]
Long-term debt	579	586
1.95% Notes Due October 2030 [Member]
Debt Instrument [Line Items]
Long-term debt	500	$ 500
Notes interest rate, percentage		1.95%
Proceeds from issuance of debt		$ 500
6.0% notes due August 2032 [Member]
Debt Instrument [Line Items]
Long-term debt	250	250
6.125% notes due April 2039 [Member]
Debt Instrument [Line Items]
Long-term debt	250	250
5.25% notes due November 2039 [Member]
Debt Instrument [Line Items]
Long-term debt	300	300
2.75% Notes Due October 2050 [Member]
Debt Instrument [Line Items]
Long-term debt	500	$ 500
Notes interest rate, percentage		2.75%
Proceeds from issuance of debt		$ 500
Other [Member]
Debt Instrument [Line Items]
Long-term debt	$ 44	$ 40