Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Mar. 31, 2023	Mar. 31, 2022	Mar. 31, 2023	Mar. 31, 2022	Sep. 30, 2022
Accumulated other comprehensive income [Roll Forward]
Beginning balance			$ 16,316
Other Comprehensive Income (Loss) Net of Tax, Period Change [Abstract]
Ending balance	$ 17,347	$ 10,614	17,347	$ 10,614
Accumulated other comprehensive income (loss)	(1,148)	(957)	(1,148)	(957)	$ (1,485)
Foreign currency translation, tax	4	(8)	32	(18)
Amortization of deferred actuarial losses, tax	3	(5)	7	(10)
Gains (losses) deferred during the period, tax	(6)	(5)	(9)	(9)
Reclassification of (gains) losses to sales and cost of sales, tax	2	4	2	6
Accumulated other comprehensive income (loss)
Accumulated other comprehensive income [Roll Forward]
Beginning balance	(1,255)	(922)	(1,485)	(872)
Other Comprehensive Income (Loss) Net of Tax, Period Change [Abstract]
Ending balance	(1,148)	(957)	(1,148)	(957)
Foreign currency translation [Member]
Accumulated other comprehensive income [Roll Forward]
Beginning balance	(1,029)	(701)	(1,265)	(629)
Other Comprehensive Income (Loss) Net of Tax, Period Change [Abstract]
Other comprehensive income (loss), foreign currency translation, net of tax of $XX, $(8), $XX and $(18), respectively	111	(59)	347	(131)
Ending balance	(918)	(760)	(918)	(760)
Pension and post retirement [Member]
Accumulated other comprehensive income [Roll Forward]
Beginning balance	(238)	(241)	(222)	(259)
Other Comprehensive Income (Loss) Net of Tax, Period Change [Abstract]
Amortization of deferred actuarial losses into earnings, net of tax of $X, $(5), $X and $(10), respectively	(17)	18	(33)	36
Ending balance	(255)	(223)	(255)	(223)
Cash Flow Hedges [Member]
Accumulated other comprehensive income [Roll Forward]
Beginning balance	12	20	2	16
Other Comprehensive Income (Loss) Net of Tax, Period Change [Abstract]
Deferral of gains (losses) arising during the period, net of tax of $(X), $5, $(X) and $(9), respectively	18	17	27	29
Reclassification of realized gains (losses) to sales and cost of sales, net of tax of $X, $4, $X and $6, respectively	(5)	(11)	(4)	(19)
Ending balance	$ 25	$ 26	$ 25	$ 26