Retirement Plans - Funded Status (Details) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2020
Change in Projected Benefit Obligation:
Service cost	$ 7	$ 8	$ 7
Interest cost	10	9	10
Pension plan
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Accumulated Benefit Obligation	322	552
Change in Projected Benefit Obligation:
Projected benefit obligation at beginning of year	574	606
Service cost	7	8
Interest cost	11	9
Plan participant contributions	0	0
Actuarial (gain) loss	(169)	(29)
Benefits paid	(20)	(20)
Settlements and curtailments	0	(16)
Divestitures	0	(2)
Currency translation adjustment	(63)	18
Projected benefit obligation at end of year	340	574	606
Change in Plan Assets:
Fair value of plan assets at beginning of year	493	486
Actual return on plan assets	(149)	4
Employer contributions/(distributions)	16	23
Benefits paid	(20)	(20)
Settlements and curtailments	(1)	(16)
Currency translation adjustment	(56)	16
Fair value of plan assets at end of year	283	493	$ 486
Funded status	(57)	(81)
Prepaid benefit cost | Pension plan
Change in Plan Assets:
Funded status	35	51
Accrued benefit liability | Pension plan
Change in Plan Assets:
Funded status	$ (92)	$ (132)