Property, Equipment and Technology, Net - Summary of Property, Equipment and Technology, Net (Detail) - USD ($) $ in Millions	Sep. 30, 2019	Sep. 30, 2018
Property, Plant and Equipment [Line Items]
Total property, equipment and technology	$ 6,570	$ 5,697
Accumulated depreciation and amortization	(3,875)	(3,225)
Property, equipment and technology, net	2,695	2,472
Land
Property, Plant and Equipment [Line Items]
Total property, equipment and technology	71	69
Buildings and building improvements
Property, Plant and Equipment [Line Items]
Total property, equipment and technology	965	898
Furniture, equipment and leasehold improvements
Property, Plant and Equipment [Line Items]
Total property, equipment and technology	1,913	1,661
Construction-in-progress
Property, Plant and Equipment [Line Items]
Total property, equipment and technology	180	153
Technology
Property, Plant and Equipment [Line Items]
Total property, equipment and technology	$ 3,441	$ 2,916