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		Jun. 30, 2017	Dec. 31, 2016
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities Acquired During Period [Line Items]
Financing Receivable, Recorded Investment, Past Due		$ 265	$ 309
Financing Receivable, Recorded Investment, Current		43,418	42,340
Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due		124	150
Financing Receivable Recorded Investments, Equal To and Greater Than 90 Days Past Due		141	159
Loans and Leases Receivable, Gross		43,683	42,649
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing		19	36
Financing Receivable, Recorded Investment, Nonaccrual Status	[1]	325	381
Commercial		40	49
Certain Loans Acquired In Transfer Not Accounted For As Debt Securities Commercial Real Estate		15	51
Consumer		7	9
Outstanding balance		62	109
Certain Loans Acquired in Transfer Accounted for as Debt Securities, Carrying Amount, Net		43	77
ALLL		0	1
Carrying amount, net		43	76
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		3	0
Financing Receivable, Recorded Investment, Current		50	172
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		3	0
Loans and Leases Receivable, Gross		53	172
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing		0	0
Financing Receivable, Recorded Investment, Nonaccrual Status	[1]	9	40
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		115	146
Financing Receivable, Recorded Investment, Current		13,735	13,306
Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due		54	72
Financing Receivable Recorded Investments, Equal To and Greater Than 90 Days Past Due		61	74
Loans and Leases Receivable, Gross		13,850	13,452
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing		10	10
Financing Receivable, Recorded Investment, Nonaccrual Status	[1]	216	287
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		0	0
Financing Receivable, Recorded Investment, Current		387	423
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	0
Loans and Leases Receivable, Gross		387	423
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing		0	0
Financing Receivable, Recorded Investment, Nonaccrual Status	[1]	10	14
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		60	68
Financing Receivable, Recorded Investment, Current		7,035	6,894
Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due		26	40
Financing Receivable Recorded Investments, Equal To and Greater Than 90 Days Past Due		34	28
Loans and Leases Receivable, Gross		7,095	6,962
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing		3	8
Financing Receivable, Recorded Investment, Nonaccrual Status	[1]	52	43
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		871	778
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	0
Loans and Leases Receivable, Gross		871	778
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing		0	0
Financing Receivable, Recorded Investment, Nonaccrual Status	[1]	1	1
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		175	214
Financing Receivable, Recorded Investment, Current		22,028	21,401
Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due		80	112
Financing Receivable Recorded Investments, Equal To and Greater Than 90 Days Past Due		95	102
Loans and Leases Receivable, Gross		22,203	21,615
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing		13	18
Financing Receivable, Recorded Investment, Nonaccrual Status	[1]	279	345
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		11	9
Financing Receivable, Recorded Investment, Current		2,175	2,010
Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due		6	7
Financing Receivable Recorded Investments, Equal To and Greater Than 90 Days Past Due		5	2
Loans and Leases Receivable, Gross		2,186	2,019
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing		0	1
Financing Receivable, Recorded Investment, Nonaccrual Status	[1]	1	1
Term [Member]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities Acquired During Period [Line Items]
Financing Receivable, Recorded Investment, Past Due		22	31
Financing Receivable, Recorded Investment, Current		8,990	9,291
Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due		12	9
Financing Receivable Recorded Investments, Equal To and Greater Than 90 Days Past Due		10	22
Loans and Leases Receivable, Gross		9,012	9,322
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing		3	12
Financing Receivable, Recorded Investment, Nonaccrual Status	[1]	24	18
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	40
Financing Receivable, Recorded Investment, Current		11,165	11,301
Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due		18	16
Financing Receivable Recorded Investments, Equal To and Greater Than 90 Days Past Due		15	24
Loans and Leases Receivable, Gross		11,198	11,341
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing		3	13
Financing Receivable, Recorded Investment, Nonaccrual Status	[1]	25	19
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		13	10
Financing Receivable, Recorded Investment, Current		2,684	2,635
Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due		6	4
Financing Receivable Recorded Investments, Equal To and Greater Than 90 Days Past Due		7	6
Loans and Leases Receivable, Gross		2,697	2,645
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing		2	1
Financing Receivable, Recorded Investment, Nonaccrual Status	[1]	4	5
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		31	34
Financing Receivable, Recorded Investment, Current		6,328	5,857
Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due		10	12
Financing Receivable Recorded Investments, Equal To and Greater Than 90 Days Past Due		21	22
Loans and Leases Receivable, Gross		6,359	5,891
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing		0	0
Financing Receivable, Recorded Investment, Nonaccrual Status	[1]	17	11
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		7	7
Financing Receivable, Recorded Investment, Current		553	479
Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due		6	3
Financing Receivable Recorded Investments, Equal To and Greater Than 90 Days Past Due		1	4
Loans and Leases Receivable, Gross		560	486
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing		0	3
Financing Receivable, Recorded Investment, Nonaccrual Status	[1]	0	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		5	3
Financing Receivable, Recorded Investment, Current		473	478
Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due		3	2
Financing Receivable Recorded Investments, Equal To and Greater Than 90 Days Past Due		2	1
Loans and Leases Receivable, Gross		478	481
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing		1	1
Financing Receivable, Recorded Investment, Nonaccrual Status	[1]	0	1
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		187	189
Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due		1	1
Financing Receivable Recorded Investments, Equal To and Greater Than 90 Days Past Due		0	0
Loans and Leases Receivable, Gross		188	190
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing		0	0
Financing Receivable, Recorded Investment, Nonaccrual Status	[1]	0	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		57	55
Financing Receivable, Recorded Investment, Current		10,225	9,638
Financing Receivable Recorded Investment Thirty To Eighty Nine Days Past Due		26	22
Financing Receivable Recorded Investments, Equal To and Greater Than 90 Days Past Due		31	33
Loans and Leases Receivable, Gross		10,282	9,693
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing		3	5
Financing Receivable, Recorded Investment, Nonaccrual Status	[1]	$ 21	$ 17

[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.