Fair Value Measurements (Assets And Liabilities Recorded At Fair Value On A Recurring Basis) (Details) - USD ($) $ in Millions		Sep. 30, 2022	Dec. 31, 2021
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale		$ 19,452	$ 16,986
Derivative assets		1,617	928
Derivative liabilities		2,131	747
U.S. Treasury and other U.S. government agency securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale		2,756	2,993
Residential Mortgage Backed Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale	[1]	12,052	13,288
Commercial Mortgage Backed Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale	[1]	4,644	705
Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale		19,452	16,986
Derivative assets		1,617	928
Total assets at fair value		21,209	18,089
Derivative liabilities		2,143	760
Deferred compensation plan liabilities		87	113
Total liabilities at fair value		2,230	873
Recurring | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale		2,756	2,993
Derivative assets		0	0
Total assets at fair value		2,896	3,168
Derivative liabilities		0	0
Deferred compensation plan liabilities		87	113
Total liabilities at fair value		87	113
Recurring | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale		16,696	13,993
Derivative assets		1,617	902
Total assets at fair value		18,313	14,895
Derivative liabilities		2,131	747
Deferred compensation plan liabilities		0	0
Total liabilities at fair value		2,131	747
Recurring | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale		0	0
Derivative assets		0	26
Total assets at fair value		0	26
Derivative liabilities		12	13
Deferred compensation plan liabilities		0	0
Total liabilities at fair value		12	13
Recurring | Interest rate contracts
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets		212	239
Derivative liabilities		741	69
Recurring | Interest rate contracts | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets		0	0
Derivative liabilities		0	0
Recurring | Interest rate contracts | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets		212	213
Derivative liabilities		741	69
Recurring | Interest rate contracts | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets		0	26
Derivative liabilities		0	0
Recurring | Energy contracts
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets		1,325	670
Derivative liabilities		1,316	662
Recurring | Energy contracts | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets		0	0
Derivative liabilities		0	0
Recurring | Energy contracts | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets		1,325	670
Derivative liabilities		1,316	662
Recurring | Energy contracts | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets		0	0
Derivative liabilities		0	0
Recurring | Foreign exchange contracts
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets		80	19
Derivative liabilities		74	16
Recurring | Foreign exchange contracts | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets		0	0
Derivative liabilities		0	0
Recurring | Foreign exchange contracts | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets		80	19
Derivative liabilities		74	16
Recurring | Foreign exchange contracts | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets		0	0
Derivative liabilities		0	0
Recurring | Other financial derivative
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liabilities		12	13
Recurring | Other financial derivative | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liabilities		0	0
Recurring | Other financial derivative | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liabilities		0	0
Recurring | Other financial derivative | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total liabilities at fair value		12	13
Recurring | Deferred compensation plan assets
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Deferred compensation plan assets		87	113
Recurring | Deferred compensation plan assets | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Deferred compensation plan assets		87	113
Recurring | Deferred compensation plan assets | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Deferred compensation plan assets		0	0
Recurring | Deferred compensation plan assets | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Deferred compensation plan assets		0	0
Recurring | Equity and other non-debt securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity securities		53	62
Recurring | Equity and other non-debt securities | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity securities		53	62
Recurring | Equity and other non-debt securities | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity securities		0	0
Recurring | Equity and other non-debt securities | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity securities		0	0
Recurring | U.S. Treasury and other U.S. government agency securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale		2,756	2,993
Recurring | U.S. Treasury and other U.S. government agency securities | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale		2,756	2,993
Recurring | U.S. Treasury and other U.S. government agency securities | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale		0	0
Recurring | U.S. Treasury and other U.S. government agency securities | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale		0	0
Recurring | Residential Mortgage Backed Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale	[1]	12,052	13,288
Recurring | Residential Mortgage Backed Securities | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale	[1]	0	0
Recurring | Residential Mortgage Backed Securities | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale	[1]	12,052	13,288
Recurring | Residential Mortgage Backed Securities | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale	[1]	0	0
Recurring | Commercial Mortgage Backed Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale	[1]	4,644	705
Recurring | Commercial Mortgage Backed Securities | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale	[1]	0	0
Recurring | Commercial Mortgage Backed Securities | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale	[1]	4,644	705
Recurring | Commercial Mortgage Backed Securities | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment securities available-for-sale	[1]	$ 0	$ 0

[1] Issued and/or guaranteed by U.S. government agencies or U.S. government-sponsored enterprises.