Derivatives - Derivatives Associated with Fixed Income Trading Activities (Details) - USD ($) $ in Millions	Mar. 31, 2026	Dec. 31, 2025
Customer interest rate contracts
Derivative Instruments, Gain (Loss) [Line Items]
Notional	$ 4,201	$ 4,301
Assets	13	22
Liabilities	108	104
Offsetting upstream interest rate contracts
Derivative Instruments, Gain (Loss) [Line Items]
Notional	4,335	4,446
Assets	74	70
Liabilities	13	22
Forwards and futures purchased
Derivative Instruments, Gain (Loss) [Line Items]
Notional	3,552	1,937
Assets	5	7
Liabilities	16	0
Forwards and futures sold
Derivative Instruments, Gain (Loss) [Line Items]
Notional	3,849	2,210
Assets	19	0
Liabilities	$ 2	$ 8