Derivative Financial Instruments - Net Gains (Losses) Relating to Derivative Instruments Designated as Cash Flow Hedges (Details) - Cash Flow Hedging - Interest Income (Expense) Net - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Derivative Instruments, Gain (Loss) [Line Items]
Amount of pre-tax net (losses) gains recognized in OCI	$ (185)	$ 611	$ 348
Amount of pre-tax net gains reclassified from OCI into net income	$ 293	$ 237	$ 16