Derivative Financial Instruments and Hedging Activities (Schedule of Derivative Instruments Notional and Fair Value) (Details) - USD ($) $ in Millions	Sep. 30, 2022	Dec. 31, 2021
Derivatives, Fair Value [Line Items]
Notional Amount	$ 160,635	$ 138,062
Derivative Asset, Fair Value, Gross Asset	2,837	1,111
Derivative Liabilities, Fair Value, Gross Liability	3,695	1,012
Derivative Asset netting adjustments	2,646	699
Derivative Liability, netting adjustments	2,106	932
Derivative Assets	191	412
Derivative Liabilities	1,589	80
Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Notional Amount	41,023	28,550
Derivative Asset, Fair Value, Gross Asset	42	171
Derivative Liabilities, Fair Value, Gross Liability	931	61
Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Notional Amount	119,612	109,512
Derivative Asset, Fair Value, Gross Asset	2,795	940
Derivative Liabilities, Fair Value, Gross Liability	2,764	951
Interest Rate Swaps [Member] \| Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Notional Amount	89,472	81,327
Interest Rate Swaps [Member] \| Not Designated as Hedging Instrument [Member] \| Other Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	2,350	748
Interest Rate Swaps [Member] \| Not Designated as Hedging Instrument [Member] \| Other Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative Liabilities, Fair Value, Gross Liability	2,418	794
Interest Rate Options [Member] \| Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Notional Amount	16,844	15,990
Interest Rate Options [Member] \| Not Designated as Hedging Instrument [Member] \| Other Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	122	48
Interest Rate Options [Member] \| Not Designated as Hedging Instrument [Member] \| Other Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative Liabilities, Fair Value, Gross Liability	111	19
Interest Rate Futures And Forward Commitments [Member] \| Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Notional Amount	1,771	2,739
Interest Rate Futures And Forward Commitments [Member] \| Not Designated as Hedging Instrument [Member] \| Other Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	27	11
Interest Rate Futures And Forward Commitments [Member] \| Not Designated as Hedging Instrument [Member] \| Other Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative Liabilities, Fair Value, Gross Liability	5	3
Other Contract [Member] \| Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Notional Amount	11,525	9,456
Other Contract [Member] \| Not Designated as Hedging Instrument [Member] \| Other Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	296	133
Other Contract [Member] \| Not Designated as Hedging Instrument [Member] \| Other Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative Liabilities, Fair Value, Gross Liability	230	135
Fair Value Hedging [Member] \| Interest Rate Swaps [Member] \| Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Notional Amount	7,923	7,900
Fair Value Hedging [Member] \| Interest Rate Swaps [Member] \| Designated as Hedging Instrument [Member] \| Other Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	41	0
Fair Value Hedging [Member] \| Interest Rate Swaps [Member] \| Designated as Hedging Instrument [Member] \| Other Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative Liabilities, Fair Value, Gross Liability	168	32
Cash Flow Hedging [Member] \| Interest Rate Swaps [Member] \| Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Notional Amount	33,100	20,650
Cash Flow Hedging [Member] \| Interest Rate Swaps [Member] \| Designated as Hedging Instrument [Member] \| Other Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	1	171
Cash Flow Hedging [Member] \| Interest Rate Swaps [Member] \| Designated as Hedging Instrument [Member] \| Other Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative Liabilities, Fair Value, Gross Liability	$ 763	$ 29

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