PROPERTY AND EQUIPMENT, NET (Details) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2023
Property, Plant and Equipment [Line Items]
Gross carrying value	$ 1,993	$ 1,821
Accumulated depreciation/ software amortization	(1,323)	(1,186)
Property and equipment, net	670	635
Depreciation expense	68	58	$ 51
Amortization expense associated with computer software	86	77	$ 69
Land
Property, Plant and Equipment [Line Items]
Gross carrying value	30	30
Accumulated depreciation/ software amortization	0	0
Property and equipment, net	30	30
Software, including development in progress
Property, Plant and Equipment [Line Items]
Gross carrying value	959	870
Accumulated depreciation/ software amortization	(648)	(568)
Property and equipment, net	311	302
Buildings, building components, leasehold and land improvements
Property, Plant and Equipment [Line Items]
Gross carrying value	488	465
Accumulated depreciation/ software amortization	(279)	(263)
Property and equipment, net	209	202
Furniture, fixtures and equipment
Property, Plant and Equipment [Line Items]
Gross carrying value	516	456
Accumulated depreciation/ software amortization	(396)	(355)
Property and equipment, net	$ 120	$ 101