Occupancy Expense and Information Systems and Communications Expense - Narrative (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Expenses [Line Items]
Depreciation and amortization	$ 892	$ 824	$ 829
Finance lease right-of-use asset	89	67
Finance lease liability	106	79
Accumulated amortization for finance lease right-of-use assets	182
Interest on lease liabilities	$ 3	$ 3
Operating Lease, Right-of-Use Asset, Statement of Financial Position [Extensible List]	Other assets	Other assets
Right-of-use assets	$ 865	$ 818
Operating Lease, Liability, Statement of Financial Position [Extensible List]	Accrued expenses and other liabilities
Operating leases not yet commenced	$ 80
Minimum
Expenses [Line Items]
Operating leases not yet commenced, lease terms	2 years
Maximum
Expenses [Line Items]
Operating leases not yet commenced, lease terms	10 years