Derivative and Hedging Activities - Net Gain (Loss) Recognized on Designated Instruments (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Derivative Instruments, Gain (Loss) [Line Items]
Amount of gain (loss) recognized in accumulated other comprehensive loss	$ (12)	$ (16)	$ (37)	$ 7
Futures | Net return on mortgage servicing rights
Derivative Instruments, Gain (Loss) [Line Items]
Amount of gain (loss) recognized in accumulated other comprehensive loss	1	5	3	3
Interest rate swaps and swaptions | Net return on mortgage servicing rights
Derivative Instruments, Gain (Loss) [Line Items]
Amount of gain (loss) recognized in accumulated other comprehensive loss	(3)	(29)	(37)	(22)
Mortgage-backed securities forwards | Net return on mortgage servicing rights
Derivative Instruments, Gain (Loss) [Line Items]
Amount of gain (loss) recognized in accumulated other comprehensive loss	(9)	(11)	(21)	(13)
Rate lock commitments and US Treasury futures | Net gain on loan sales
Derivative Instruments, Gain (Loss) [Line Items]
Amount of gain (loss) recognized in accumulated other comprehensive loss	1	18	23	38
Interest rate swaps | Other non-interest income
Derivative Instruments, Gain (Loss) [Line Items]
Amount of gain (loss) recognized in accumulated other comprehensive loss	$ (2)	$ 1	$ (5)	$ 1