Equipment, Office Facilities, and Property - Schedule of Equipment, Office Facilities, and Property (Details) - USD ($) $ in Millions		Dec. 31, 2023	Dec. 31, 2022
Property, Plant and Equipment [Line Items]
Total equipment, office facilities, and property		$ 7,446	$ 6,947
Accumulated depreciation and amortization		(3,756)	(3,233)
Total equipment, office facilities, and property — net	[1]	3,690	3,714
Software
Property, Plant and Equipment [Line Items]
Total equipment, office facilities, and property		3,375	2,940
Buildings
Property, Plant and Equipment [Line Items]
Total equipment, office facilities, and property		1,720	1,693
Information technology and telecommunications equipment
Property, Plant and Equipment [Line Items]
Total equipment, office facilities, and property		1,133	1,008
Leasehold improvements
Property, Plant and Equipment [Line Items]
Total equipment, office facilities, and property		411	472
Land
Property, Plant and Equipment [Line Items]
Total equipment, office facilities, and property		214	209
Construction in progress
Property, Plant and Equipment [Line Items]
Total equipment, office facilities, and property		213	274
Other
Property, Plant and Equipment [Line Items]
Total equipment, office facilities, and property		$ 380	$ 351

[1] Certain prior year amounts have been reclassified to conform to the current year presentation. See Note 1 for additional information.