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		Mar. 31, 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		$ 246	$ 175
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
Loans and Leases Receivable, Gross		47,606	46,714
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing		8	10
Financing Receivable, Recorded Investment, Nonaccrual Status	[1]	138	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		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
Loans and Leases Receivable, Gross		69	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		112	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		14,758	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		312	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		52	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		7,754	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		1,774	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		165	110
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
Loans and Leases Receivable, Gross		24,598	24,162
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing		5	7
Financing Receivable, Recorded Investment, Nonaccrual Status	[1]	90	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		10	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		2,343	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		23	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		9,187	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		33	16
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
Loans and Leases Receivable, Gross		11,530	11,125
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing		2	1
Financing Receivable, Recorded Investment, Nonaccrual Status	[1]	24	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		2,884	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		34	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		7,294	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		636	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		489	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		175	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		48	49
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
Loans and Leases Receivable, Gross		11,478	11,427
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing		1	2
Financing Receivable, Recorded Investment, Nonaccrual Status	[1]	$ 24	$ 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.