Derivative and Hedging Activities - Net Gain (Loss) Recognized on Designated Instruments (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Derivative Instruments, Gain (Loss) [Line Items]
Total derivative (loss) gain	$ (31)	$ (47)	$ 11
Futures | Net return on mortgage servicing rights
Derivative Instruments, Gain (Loss) [Line Items]
Total derivative (loss) gain	2	1	(1)
Interest rate swaps and swaptions | Net return on mortgage servicing rights
Derivative Instruments, Gain (Loss) [Line Items]
Total derivative (loss) gain	(38)	(34)	(11)
Mortgage-backed securities forwards | Net return on mortgage servicing rights
Derivative Instruments, Gain (Loss) [Line Items]
Total derivative (loss) gain	(18)	(15)	(4)
Rate lock commitments and US Treasury futures | Net gain on loan sales
Derivative Instruments, Gain (Loss) [Line Items]
Total derivative (loss) gain	23	2	28
Forward commitments | Other noninterest income
Derivative Instruments, Gain (Loss) [Line Items]
Total derivative (loss) gain	0	0	(1)
Interest rate swaps | Other noninterest income
Derivative Instruments, Gain (Loss) [Line Items]
Total derivative (loss) gain	$ 0	$ (1)	$ 0