Supplemental Financial Information - Trade Receivables, Allowances for Doubtful Accounts and Cash Discounts (Detail) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2020
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Beginning Balance	$ 91	$ 88	$ 83
Additions charged to costs and expenses	77	101	62
Deductions and other	(87)	(97)	(57)
Ending Balance	81	91	88
Allowance for Doubtful Accounts
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Beginning Balance	73	76	72
Additions charged to costs and expenses	4	17	39
Deductions and other	(12)	(20)	(35)
Ending Balance	65	73	76
Allowance for Cash Discounts
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Beginning Balance	18	12	11
Additions charged to costs and expenses	73	84	23
Deductions and other	(75)	(77)	(22)
Ending Balance	$ 16	$ 18	$ 12