Loans And Allowance For Credit Losses (Summary Of Past Due Loans (Accruing And Nonaccruing)) (Details) - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment		$ 5	$ 2
Financing Receivable, Recorded Investment, Current		47,360		$ 46,539
Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due		167		89
Financing Receivable Recorded Investments, Equal To and Greater Than 90 Days Past Due		79		86
Financing Receivable, Recorded Investment, Past Due		246		175
Loans and Leases Receivable, Gross		47,606		46,714
Accruing loans 90+ days past due		8		10
Financing Receivable, Recorded Investment, Nonaccrual Status	[1]	138		145
Bankcard And Other Revolving Plans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Recorded Investment, Nonaccrual Status		0		1
Commercial And Industrial [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment		3	1
Financing Receivable, Recorded Investment, Nonaccrual Status		72		82
Commercial [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans and Leases Receivable, Gross		24,598		24,162
Commercial Loan [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment		3	2
Financing Receivable, Recorded Investment, Nonaccrual Status		143		152
Consumer Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans and Leases Receivable, Gross		11,478		11,427
Financing Receivable, Recorded Investment, Nonaccrual Status		0		0
Consumer Loan [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Recorded Investment, Nonaccrual Status		58		56
Finance Leases Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Recorded Investment, Nonaccrual Status		1		2
Owner Occupied [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment		0	1
Financing Receivable, Recorded Investment, Nonaccrual Status		69		67
Municipal [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Recorded Investment, Nonaccrual Status		1		1
Term [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment		2	0
Financing Receivable, Recorded Investment, Nonaccrual Status		32		38
Commercial Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment		2	0
Loans and Leases Receivable, Gross		11,530		11,125
Financing Receivable, Recorded Investment, Nonaccrual Status		33		38
Home Equity Line of Credit [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Recorded Investment, Nonaccrual Status		11		13
One Through Four Family Residential [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Recorded Investment, Nonaccrual Status		45		42
Construction And Other Consumer Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Recorded Investment, Nonaccrual Status		2		0
Consumer Loan [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Recorded Investment, Current		11,430		11,378
Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due		22		23
Financing Receivable Recorded Investments, Equal To and Greater Than 90 Days Past Due		26		26
Financing Receivable, Recorded Investment, Past Due		48		49
Loans and Leases Receivable, Gross		11,478		11,427
Accruing loans 90+ days past due		1		2
Financing Receivable, Recorded Investment, Nonaccrual Status	[1]	24		23
Consumer Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Recorded Investment, Current				179
Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due				1
Financing Receivable Recorded Investments, Equal To and Greater Than 90 Days Past Due				0
Financing Receivable, Recorded Investment, Past Due		1		1
Loans and Leases Receivable, Gross		175		180
Accruing loans 90+ days past due				0
Consumer Portfolio Segment [Member] | Consumer Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Recorded Investment, Current		174
Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due		1
Financing Receivable Recorded Investments, Equal To and Greater Than 90 Days Past Due		0
Accruing loans 90+ days past due		0
Financing Receivable, Recorded Investment, Nonaccrual Status	[1]	0		0
Revolving Credit Facility [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Recorded Investment, Current				487
Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due				2
Financing Receivable Recorded Investments, Equal To and Greater Than 90 Days Past Due				2
Financing Receivable, Recorded Investment, Past Due		4		4
Loans and Leases Receivable, Gross		489		491
Accruing loans 90+ days past due				2
Revolving Credit Facility [Member] | Bankcard And Other Revolving Plans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Recorded Investment, Current		485
Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due		3
Financing Receivable Recorded Investments, Equal To and Greater Than 90 Days Past Due		1
Accruing loans 90+ days past due		1
Financing Receivable, Recorded Investment, Nonaccrual Status	[1]	0		0
Construction And Other Consumer Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Recorded Investment, Current				642
Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due				1
Financing Receivable Recorded Investments, Equal To and Greater Than 90 Days Past Due				0
Financing Receivable, Recorded Investment, Past Due		0		1
Loans and Leases Receivable, Gross		636		643
Accruing loans 90+ days past due				0
Construction And Other Consumer Real Estate [Member] | Construction And Other Consumer Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Recorded Investment, Current		636
Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due		0
Financing Receivable Recorded Investments, Equal To and Greater Than 90 Days Past Due		0
Accruing loans 90+ days past due		0
Financing Receivable, Recorded Investment, Nonaccrual Status	[1]	2		0
One Through Four Family Residential [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Recorded Investment, Current				7,143
Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due				15
Financing Receivable Recorded Investments, Equal To and Greater Than 90 Days Past Due				18
Financing Receivable, Recorded Investment, Past Due		34		33
Loans and Leases Receivable, Gross		7,294		7,176
Accruing loans 90+ days past due				0
One Through Four Family Residential [Member] | One Through Four Family Residential [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Recorded Investment, Current		7,260
Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due		13
Financing Receivable Recorded Investments, Equal To and Greater Than 90 Days Past Due		21
Accruing loans 90+ days past due		0
Financing Receivable, Recorded Investment, Nonaccrual Status	[1]	17		19
Home Equity Line of Credit [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Recorded Investment, Current				2,927
Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due				4
Financing Receivable Recorded Investments, Equal To and Greater Than 90 Days Past Due				6
Financing Receivable, Recorded Investment, Past Due		9		10
Loans and Leases Receivable, Gross		2,884		2,937
Accruing loans 90+ days past due				0
Home Equity Line of Credit [Member] | Home Equity Line of Credit [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Recorded Investment, Current		2,875
Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due		5
Financing Receivable Recorded Investments, Equal To and Greater Than 90 Days Past Due		4
Accruing loans 90+ days past due		0
Financing Receivable, Recorded Investment, Nonaccrual Status	[1]	5		4
Commercial Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Recorded Investment, Current		11,497		11,109
Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due		26		5
Financing Receivable Recorded Investments, Equal To and Greater Than 90 Days Past Due		7		11
Financing Receivable, Recorded Investment, Past Due		33		16
Loans and Leases Receivable, Gross		11,530		11,125
Accruing loans 90+ days past due		2		1
Financing Receivable, Recorded Investment, Nonaccrual Status	[1]	24		26
Term [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Recorded Investment, Current				8,924
Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due				4
Financing Receivable Recorded Investments, Equal To and Greater Than 90 Days Past Due				11
Financing Receivable, Recorded Investment, Past Due		23		15
Loans and Leases Receivable, Gross		9,187		8,939
Accruing loans 90+ days past due				1
Term [Member] | Term [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Recorded Investment, Current		9,164
Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due		17
Financing Receivable Recorded Investments, Equal To and Greater Than 90 Days Past Due		6
Accruing loans 90+ days past due		1
Financing Receivable, Recorded Investment, Nonaccrual Status	[1]	24		26
Commercial Real Estate Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Recorded Investment, Current				2,185
Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due				1
Financing Receivable Recorded Investments, Equal To and Greater Than 90 Days Past Due				0
Financing Receivable, Recorded Investment, Past Due		10		1
Loans and Leases Receivable, Gross		2,343		2,186
Accruing loans 90+ days past due				0
Commercial Real Estate Portfolio Segment [Member] | Commercial Real Estate Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Recorded Investment, Current		2,333
Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due		9
Financing Receivable Recorded Investments, Equal To and Greater Than 90 Days Past Due		1
Accruing loans 90+ days past due		1
Financing Receivable, Recorded Investment, Nonaccrual Status	[1]	0		0
Commercial Loan [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Recorded Investment, Current		24,433		24,052
Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due		119		61
Financing Receivable Recorded Investments, Equal To and Greater Than 90 Days Past Due		46		49
Financing Receivable, Recorded Investment, Past Due		165		110
Loans and Leases Receivable, Gross		24,598		24,162
Accruing loans 90+ days past due		5		7
Financing Receivable, Recorded Investment, Nonaccrual Status	[1]	90		96
Municipal [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Recorded Investment, Current				1,661
Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due				0
Financing Receivable Recorded Investments, Equal To and Greater Than 90 Days Past Due				0
Financing Receivable, Recorded Investment, Past Due		0		0
Loans and Leases Receivable, Gross		1,774		1,661
Accruing loans 90+ days past due				0
Municipal [Member] | Municipal [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Recorded Investment, Current		1,774
Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due		0
Financing Receivable Recorded Investments, Equal To and Greater Than 90 Days Past Due		0
Accruing loans 90+ days past due		0
Financing Receivable, Recorded Investment, Nonaccrual Status	[1]	1		1
Owner Occupied [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Recorded Investment, Current				7,621
Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due				23
Financing Receivable Recorded Investments, Equal To and Greater Than 90 Days Past Due				17
Financing Receivable, Recorded Investment, Past Due		52		40
Loans and Leases Receivable, Gross		7,754		7,661
Accruing loans 90+ days past due				3
Owner Occupied [Member] | Owner Occupied [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Recorded Investment, Current		7,702
Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due		33
Financing Receivable Recorded Investments, Equal To and Greater Than 90 Days Past Due		19
Accruing loans 90+ days past due		1
Financing Receivable, Recorded Investment, Nonaccrual Status	[1]	45		48
Finance Leases Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Recorded Investment, Current				325
Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due				1
Financing Receivable Recorded Investments, Equal To and Greater Than 90 Days Past Due				1
Financing Receivable, Recorded Investment, Past Due		1		2
Loans and Leases Receivable, Gross		312		327
Accruing loans 90+ days past due				0
Finance Leases Portfolio Segment [Member] | Finance Leases Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Recorded Investment, Current		311
Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due		0
Financing Receivable Recorded Investments, Equal To and Greater Than 90 Days Past Due		1
Accruing loans 90+ days past due		0
Financing Receivable, Recorded Investment, Nonaccrual Status	[1]	1		1
Commercial And Industrial [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Recorded Investment, Current				14,445
Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due				37
Financing Receivable Recorded Investments, Equal To and Greater Than 90 Days Past Due				31
Financing Receivable, Recorded Investment, Past Due		112		68
Loans and Leases Receivable, Gross		14,758		14,513
Accruing loans 90+ days past due				4
Commercial And Industrial [Member] | Commercial And Industrial [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Recorded Investment, Current		14,646
Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due		86
Financing Receivable Recorded Investments, Equal To and Greater Than 90 Days Past Due		26
Accruing loans 90+ days past due		4
Financing Receivable, Recorded Investment, Nonaccrual Status	[1]	43		46
loans held for sale [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Recorded Investment, Current		69		89
Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due		0		0
Financing Receivable Recorded Investments, Equal To and Greater Than 90 Days Past Due		0		4
Financing Receivable, Recorded Investment, Past Due		0		4
Loans and Leases Receivable, Gross		69		93
Accruing loans 90+ days past due		0		0
Financing Receivable, Recorded Investment, Nonaccrual Status	[1]	0		$ 2
Accruing [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment		0	0
Accruing [Member] | Commercial And Industrial [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment		0	0
Accruing [Member] | Commercial Loan [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment		0	0
Accruing [Member] | Owner Occupied [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment		0	0
Accruing [Member] | Term [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment		0	0
Accruing [Member] | Commercial Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment		0
Nonaccruing [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment		5	2
Nonaccruing [Member] | Commercial And Industrial [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment		3	1
Nonaccruing [Member] | Commercial Loan [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment		3	2
Nonaccruing [Member] | Owner Occupied [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment		0	1
Nonaccruing [Member] | Term [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment		2	$ 0
Nonaccruing [Member] | Commercial Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Financing Receivable, Modifications, Subsequent Default, Recorded Investment		$ 2

[1] 1 Represents nonaccrual loans that are not past due more than 30 days; however, full payment of principal and interest is still not expected.