Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Millions	3 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	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	10,288	$ 8,939
Accumulated other comprehensive income (loss)	(922)	(1,330)	$ (872)
Accumulated other comprehensive income (loss)
Accumulated other comprehensive income [Roll Forward]
Beginning balance	(872)	(1,577)
Other Comprehensive Income (Loss) Net of Tax, Period Change [Abstract]
Ending balance	(922)	(1,330)
Foreign currency translation [Member]
Accumulated other comprehensive income [Roll Forward]
Beginning balance	(629)	(711)
Other Comprehensive Income (Loss) Net of Tax, Period Change [Abstract]
Other comprehensive income (loss), foreign currency translation, net of tax of $(10), and $19, respectively	(72)	189
Ending balance	(701)	(522)
Pension and post retirement [Member]
Accumulated other comprehensive income [Roll Forward]
Beginning balance	(259)	(864)
Other Comprehensive Income (Loss) Net of Tax, Period Change [Abstract]
Amortization of deferred actuarial losses into earnings, net of tax of $(5) and $(8), respectively	18	27
Ending balance	(241)	(837)
Cash Flow Hedges [Member]
Accumulated other comprehensive income [Roll Forward]
Beginning balance	16	(2)
Other Comprehensive Income (Loss) Net of Tax, Period Change [Abstract]
Deferral of gains (losses) arising during the period, net of tax of $(4) and $(11), respectively	12	34
Reclassification of realized gains (losses) to sales and cost of sales, net of tax of $2 and $1, respectively	(8)	(3)
Ending balance	$ 20	$ 29