Property, Equipment and Technology, Net (Detail) - USD ($) $ in Millions	Sep. 30, 2018	Sep. 30, 2017
Property, Plant and Equipment [Line Items]
Total property, equipment and technology	$ 5,697	$ 5,143
Accumulated depreciation and amortization	(3,225)	(2,890)
Property, equipment and technology, net	2,472	2,253
Land
Property, Plant and Equipment [Line Items]
Total property, equipment and technology	69	72
Buildings and building improvements
Property, Plant and Equipment [Line Items]
Total property, equipment and technology	898	865
Furniture, equipment and leasehold improvements
Property, Plant and Equipment [Line Items]
Total property, equipment and technology	1,661	1,534
Construction-in-progress
Property, Plant and Equipment [Line Items]
Total property, equipment and technology	153	139
Technology
Property, Plant and Equipment [Line Items]
Total property, equipment and technology	$ 2,916	$ 2,533