Derivatives - Gains/(Losses) on Derivatives Associated with Mortgage Banking Hedges (Details) - Mortgage Banking Hedges - Hedged Items - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Option contracts written
Derivative Instruments, Gain (Loss) [Line Items]
Gains (losses) on derivative instruments	$ 4	$ (3)	$ 5	$ (12)
Forward contracts written
Derivative Instruments, Gain (Loss) [Line Items]
Gains (losses) on derivative instruments	6	0	33	0
Forward contracts purchased
Derivative Instruments, Gain (Loss) [Line Items]
Gains (losses) on derivative instruments	$ 0	$ (2)	$ 0	$ 10