Occupancy Expense and Information Systems and Communications Expense - Summary of Lease Cost (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Finance lease:
Amortization of right-of-use assets	$ 50	$ 27
Interest on lease liabilities	6	6
Total finance lease expense	56	33
Sublease income	(10)	(11)
Net finance lease expense	46	22
Operating lease:
Operating lease expense	130	147
Sublease income	(16)	(18)
Net operating lease expense	114	129
Net lease expense	160	151
Cash paid for amounts included in the measurement of lease liabilities:
Operating cash flows from finance leases	6	6
Operating cash flows from operating leases	161	198
Financing cash flows from finance leases	58	47
Right-of-use assets obtained in exchange for new lease obligations:
Operating leases	88	69
Finance leases	$ 99	$ 108