SHAREHOLDERS' EQUITY, Schedule of Accumulated Other Comprehensive (Loss) Income (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Mar. 31, 2023	Mar. 31, 2022	Mar. 31, 2023	Mar. 31, 2022
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Balance beginning of period			$ 9,432
OCI:
OCI before reclassifications and taxes	$ 126	$ (412)	254	$ (477)
Amounts reclassified from AOCI, before tax	(8)	4	(13)	8
Pre-tax net OCI	118	(408)	241	(469)
Income tax effect	(25)	106	(57)	121
Total other comprehensive income/(loss), net of tax	93	(302)	184	(348)
Balance end of period	9,969	8,609	9,969	8,609
Accumulated other comprehensive (loss) income
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Balance beginning of period	(891)	(87)	(982)	(41)
OCI:
Balance end of period	(798)	(389)	(798)	(389)
Subtotal: net investment hedges and currency translations
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Balance beginning of period	(77)	(9)	(123)	(9)
OCI:
OCI before reclassifications and taxes	7	(14)	48	(15)
Amounts reclassified from AOCI, before tax	0	0	0	0
Pre-tax net OCI	7	(14)	48	(15)
Income tax effect	0	3	5	4
Total other comprehensive income/(loss), net of tax	7	(11)	53	(11)
Balance end of period	(70)	(20)	(70)	(20)
Net investment hedges
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Balance beginning of period	139	80	153	81
OCI:
OCI before reclassifications and taxes	(4)	(12)	(23)	(14)
Amounts reclassified from AOCI, before tax	0	0	0	0
Pre-tax net OCI	(4)	(12)	(23)	(14)
Income tax effect	1	3	6	4
Total other comprehensive income/(loss), net of tax	(3)	(9)	(17)	(10)
Balance end of period	136	71	136	71
Currency translations
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Balance beginning of period	(216)	(89)	(276)	(90)
OCI:
OCI before reclassifications and taxes	11	(2)	71	(1)
Amounts reclassified from AOCI, before tax	0	0	0	0
Pre-tax net OCI	11	(2)	71	(1)
Income tax effect	(1)	0	(1)	0
Total other comprehensive income/(loss), net of tax	10	(2)	70	(1)
Balance end of period	(206)	(91)	(206)	(91)
Available- for-sale securities
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Balance beginning of period	(855)	(60)	(902)	(5)
OCI:
OCI before reclassifications and taxes	126	(433)	211	(505)
Amounts reclassified from AOCI, before tax	0	0	0	0
Pre-tax net OCI	126	(433)	211	(505)
Income tax effect	(29)	113	(67)	130
Total other comprehensive income/(loss), net of tax	97	(320)	144	(375)
Balance end of period	(758)	(380)	(758)	(380)
Cash flow hedges
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Balance beginning of period	41	(18)	43	(27)
OCI:
OCI before reclassifications and taxes	(7)	35	(5)	43
Amounts reclassified from AOCI, before tax	(8)	4	(13)	8
Pre-tax net OCI	(15)	39	(18)	51
Income tax effect	4	(10)	5	(13)
Total other comprehensive income/(loss), net of tax	(11)	29	(13)	38
Balance end of period	$ 30	$ 11	$ 30	$ 11