Loans And Allowance For Credit Losses (Schedule Of Outstanding Balances Of All Required Payments And The Related Carrying Amounts For PCI Loans) (Details) - USD ($) $ in Millions		Sep. 30, 2019	Dec. 31, 2018
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities Acquired During Period [Line Items]
Financing Receivable, Recorded Investment, Past Due		$ 197	$ 175
Financing Receivable, Recorded Investment, Current		48,638	46,539
Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due		109	89
Financing Receivable Recorded Investments, Equal To and Greater Than 90 Days Past Due		88	86
Loans and Leases Receivable, Gross		48,835	46,714
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing		6	10
Financing Receivable, Recorded Investment, Nonaccrual Status	[1]	125	145
loans held for sale [Member]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities Acquired During Period [Line Items]
Financing Receivable, Recorded Investment, Past Due		0	4
Financing Receivable, Recorded Investment, Current		141	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
Loans and Leases Receivable, Gross		141	93
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing		0	0
Financing Receivable, Recorded Investment, Nonaccrual Status	[1]	0	2
Commercial And Industrial [Member]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities Acquired During Period [Line Items]
Financing Receivable, Recorded Investment, Past Due		80	68
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
Loans and Leases Receivable, Gross		14,846	14,513
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing			4
Finance Leases Portfolio Segment [Member]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities Acquired During Period [Line Items]
Financing Receivable, Recorded Investment, Past Due		1	2
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
Loans and Leases Receivable, Gross		332	327
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing			0
Owner Occupied [Member]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities Acquired During Period [Line Items]
Financing Receivable, Recorded Investment, Past Due		49	40
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
Loans and Leases Receivable, Gross		7,924	7,661
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing			3
Municipal [Member]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities Acquired During Period [Line Items]
Financing Receivable, Recorded Investment, Past Due		0	0
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
Loans and Leases Receivable, Gross		2,185	1,661
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing			0
Commercial Loan [Member]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities Acquired During Period [Line Items]
Financing Receivable, Recorded Investment, Past Due		130	110
Financing Receivable, Recorded Investment, Current		25,157	24,052
Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due		78	61
Financing Receivable Recorded Investments, Equal To and Greater Than 90 Days Past Due		52	49
Loans and Leases Receivable, Gross		25,287	24,162
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing		5	7
Financing Receivable, Recorded Investment, Nonaccrual Status	[1]	82	96
Commercial Real Estate Portfolio Segment [Member]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities Acquired During Period [Line Items]
Financing Receivable, Recorded Investment, Past Due		1	1
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
Loans and Leases Receivable, Gross		2,347	2,186
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing			0
Term [Member]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities Acquired During Period [Line Items]
Financing Receivable, Recorded Investment, Past Due		13	15
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
Loans and Leases Receivable, Gross		9,469	8,939
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing			1
Commercial Real Estate [Member]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities Acquired During Period [Line Items]
Financing Receivable, Recorded Investment, Past Due		14	16
Financing Receivable, Recorded Investment, Current		11,802	11,109
Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due		8	5
Financing Receivable Recorded Investments, Equal To and Greater Than 90 Days Past Due		6	11
Loans and Leases Receivable, Gross		11,816	11,125
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing		0	1
Financing Receivable, Recorded Investment, Nonaccrual Status	[1]	23	26
Home Equity Line of Credit [Member]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities Acquired During Period [Line Items]
Financing Receivable, Recorded Investment, Past Due		9	10
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
Loans and Leases Receivable, Gross		2,930	2,937
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing			0
One Through Four Family Residential [Member]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities Acquired During Period [Line Items]
Financing Receivable, Recorded Investment, Past Due		39	33
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
Loans and Leases Receivable, Gross		7,506	7,176
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing			0
Construction And Other Consumer Real Estate [Member]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities Acquired During Period [Line Items]
Financing Receivable, Recorded Investment, Past Due		0	1
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
Loans and Leases Receivable, Gross		637	643
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing			0
Revolving Credit Facility [Member]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities Acquired During Period [Line Items]
Financing Receivable, Recorded Investment, Past Due		4	4
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
Loans and Leases Receivable, Gross		494	491
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing			2
Consumer Portfolio Segment [Member]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities Acquired During Period [Line Items]
Financing Receivable, Recorded Investment, Past Due		1	1
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
Loans and Leases Receivable, Gross		165	180
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing			0
Consumer Loan [Member]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities Acquired During Period [Line Items]
Financing Receivable, Recorded Investment, Past Due		53	49
Financing Receivable, Recorded Investment, Current		11,679	11,378
Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due		23	23
Financing Receivable Recorded Investments, Equal To and Greater Than 90 Days Past Due		30	26
Loans and Leases Receivable, Gross		11,732	11,427
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing		1	2
Financing Receivable, Recorded Investment, Nonaccrual Status	[1]	$ 20	$ 23

[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.