Derivative Financial Instruments - Fair Value Hedges (Details) - Other assets - Interest rate swaps - Derivatives designated as hedging instruments $ in Millions	Dec. 31, 2021 USD ($)
Derivative [Line Items]
Amortized Cost Basis of the Hedged Assets	$ 15,260
Cumulative Amount of Fair Value Hedging Adjustment Included in the Carrying Amount of the Hedged Assets	(125)
Amortized cost of hedged items where the hedged item is the last layer expected to be remaining at the end of the hedging relationship	11,200
Amount of hedged items where the hedged item is the last layer expected to be remaining at the end of the hedging relationship	6,700
Cumulative adjustments of hedged items where the hedged item is the last layer expected to be remaining at the end of the hedging relationship	83
Hedging adjustments on discontinued heading relationships	$ 6