SHAREHOLDERS' EQUITY, Schedule of Accumulated Other Comprehensive (Loss) Income (Details) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2022
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Balance, beginning of year	$ 10,187	$ 9,432
OCI:
OCI before reclassifications and taxes	641	42	$ (1,214)
Amounts reclassified from AOCI, before tax	(35)	(32)	9
Pre-tax net OCI	606	10	(1,205)
Income tax effect	(137)	1	264
Total other comprehensive income/(loss), net of tax	469	11	(941)
Balance, end of year	11,667	10,187	9,432
Accumulated other comprehensive (loss) income
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Balance, beginning of year	(971)	(982)	(41)
OCI:
Balance, end of year	(502)	(971)	(982)
Subtotal: net investment hedges and currency translations
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Balance, beginning of year	(73)	(123)	(9)
OCI:
OCI before reclassifications and taxes	49	46	(91)
Amounts reclassified from AOCI, before tax	0	0	0
Pre-tax net OCI	49	46	(91)
Income tax effect	0	4	(23)
Total other comprehensive income/(loss), net of tax	49	50	(114)
Balance, end of year	(24)	(73)	(123)
Net investment hedges
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Balance, beginning of year	143	153	81
OCI:
OCI before reclassifications and taxes	2	(14)	95
Amounts reclassified from AOCI, before tax	0	0	0
Pre-tax net OCI	2	(14)	95
Income tax effect	0	4	(23)
Total other comprehensive income/(loss), net of tax	2	(10)	72
Balance, end of year	145	143	153
Currency translations
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Balance, beginning of year	(216)	(276)	(90)
OCI:
OCI before reclassifications and taxes	47	60	(186)
Amounts reclassified from AOCI, before tax	0	0	0
Pre-tax net OCI	47	60	(186)
Income tax effect	0	0	0
Total other comprehensive income/(loss), net of tax	47	60	(186)
Balance, end of year	(169)	(216)	(276)
Available-for-sale securities
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Balance, beginning of year	(942)	(902)	(5)
OCI:
OCI before reclassifications and taxes	606	(37)	(1,208)
Amounts reclassified from AOCI, before tax	0	0	0
Pre-tax net OCI	606	(37)	(1,208)
Income tax effect	(149)	(3)	311
Total other comprehensive income/(loss), net of tax	457	(40)	(897)
Balance, end of year	(485)	(942)	(902)
Cash flow hedges
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Balance, beginning of year	44	43	(27)
OCI:
OCI before reclassifications and taxes	(14)	33	85
Amounts reclassified from AOCI, before tax	(35)	(32)	9
Pre-tax net OCI	(49)	1	94
Income tax effect	12	0	(24)
Total other comprehensive income/(loss), net of tax	(37)	1	70
Balance, end of year	$ 7	$ 44	$ 43