Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021	Sep. 30, 2021
Accumulated other comprehensive income [Roll Forward]
Beginning balance			$ 9,923
Other Comprehensive Income (Loss) Net of Tax, Period Change [Abstract]
Ending balance	$ 16,287	$ 9,339	16,287	$ 9,339
Accumulated other comprehensive income (loss)	(1,152)	(1,307)	(1,152)	(1,307)	$ (872)
Accumulated other comprehensive income (loss)
Accumulated other comprehensive income [Roll Forward]
Beginning balance	(957)	(1,322)	(872)	(1,577)
Other Comprehensive Income (Loss) Net of Tax, Period Change [Abstract]
Ending balance	(1,152)	(1,307)	(1,152)	(1,307)
Foreign currency translation [Member]
Accumulated other comprehensive income [Roll Forward]
Beginning balance	(760)	(542)	(629)	(711)
Other Comprehensive Income (Loss) Net of Tax, Period Change [Abstract]
Other comprehensive income (loss), foreign currency translation, net of tax of $(20), $(1), $(38) and $5, respectively	(186)	(6)	(317)	163
Ending balance	(946)	(548)	(946)	(548)
Pension and post retirement [Member]
Accumulated other comprehensive income [Roll Forward]
Beginning balance	(223)	(810)	(259)	(864)
Other Comprehensive Income (Loss) Net of Tax, Period Change [Abstract]
Amortization of deferred actuarial losses into earnings, net of tax of $(5), $(8), $(15) and $(24), respectively	18	27	54	81
Ending balance	(205)	(783)	(205)	(783)
Cash Flow Hedges [Member]
Accumulated other comprehensive income [Roll Forward]
Beginning balance	26	30	16	(2)
Other Comprehensive Income (Loss) Net of Tax, Period Change [Abstract]
Deferral of gains (losses) arising during the period, net of tax of $5, $(2), $(4) and $(15), respectively	(15)	7	14	50
Reclassification of realized gains (losses) to sales and cost of sales, net of tax of $4, $3, $10 and $7, respectively	(12)	(13)	(31)	(24)
Ending balance	$ (1)	$ 24	$ (1)	$ 24