Loans and Allowance for Credit Losses, PCI, by Delinquency Status, Consumer (Details) - USD ($) $ in Millions	Jun. 30, 2017	Dec. 31, 2016
PCI Loans UPB [Member] | Real estate 1-4 family first mortgage [Member]
By delinquency status:
PCI loans	$ 18,312	$ 20,803
PCI Loans UPB [Member] | Real estate 1-4 family junior lien mortgage [Member]
By delinquency status:
PCI loans	175	192
PCI Loans UPB [Member] | Residential Mortgage [Member]
By delinquency status:
PCI loans	18,487	20,995
PCI Loans Carrying Value [Member]
By delinquency status:
PCI loans	14,273	16,731
PCI Loans Carrying Value [Member] | Real estate 1-4 family first mortgage [Member]
By delinquency status:
PCI loans	13,979	16,018
PCI Loans Carrying Value [Member] | Real estate 1-4 family junior lien mortgage [Member]
By delinquency status:
PCI loans	31	36
PCI Loans Carrying Value [Member] | Residential Mortgage [Member]
By delinquency status:
PCI loans	14,010	16,054
Current-29 days past due (DPD) [Member] | Receivables Acquired with Deteriorated Credit Quality [Member] | Real estate 1-4 family first mortgage [Member]
By delinquency status:
PCI loans	14,524	16,095
Current-29 days past due (DPD) [Member] | Receivables Acquired with Deteriorated Credit Quality [Member] | Real estate 1-4 family junior lien mortgage [Member]
By delinquency status:
PCI loans	158	171
Current-29 days past due (DPD) [Member] | Receivables Acquired with Deteriorated Credit Quality [Member] | Residential Mortgage [Member]
By delinquency status:
PCI loans	14,682	16,266
Financing Receivables, 30 to 59 Days Past Due [Member] | Receivables Acquired with Deteriorated Credit Quality [Member] | Real estate 1-4 family first mortgage [Member]
By delinquency status:
PCI loans	1,229	1,488
Financing Receivables, 30 to 59 Days Past Due [Member] | Receivables Acquired with Deteriorated Credit Quality [Member] | Real estate 1-4 family junior lien mortgage [Member]
By delinquency status:
PCI loans	5	7
Financing Receivables, 30 to 59 Days Past Due [Member] | Receivables Acquired with Deteriorated Credit Quality [Member] | Residential Mortgage [Member]
By delinquency status:
PCI loans	1,234	1,495
Financing Receivables, 60 to 89 Days Past Due [Member] | Receivables Acquired with Deteriorated Credit Quality [Member] | Real estate 1-4 family first mortgage [Member]
By delinquency status:
PCI loans	574	668
Financing Receivables, 60 to 89 Days Past Due [Member] | Receivables Acquired with Deteriorated Credit Quality [Member] | Real estate 1-4 family junior lien mortgage [Member]
By delinquency status:
PCI loans	3	2
Financing Receivables, 60 to 89 Days Past Due [Member] | Receivables Acquired with Deteriorated Credit Quality [Member] | Residential Mortgage [Member]
By delinquency status:
PCI loans	577	670
90-119 Days Past Due [Member] | Receivables Acquired with Deteriorated Credit Quality [Member] | Real estate 1-4 family first mortgage [Member]
By delinquency status:
PCI loans	224	233
90-119 Days Past Due [Member] | Receivables Acquired with Deteriorated Credit Quality [Member] | Real estate 1-4 family junior lien mortgage [Member]
By delinquency status:
PCI loans	1	2
90-119 Days Past Due [Member] | Receivables Acquired with Deteriorated Credit Quality [Member] | Residential Mortgage [Member]
By delinquency status:
PCI loans	225	235
120-179 DPD member [Member] | Receivables Acquired with Deteriorated Credit Quality [Member] | Real estate 1-4 family first mortgage [Member]
By delinquency status:
PCI loans	155	238
120-179 DPD member [Member] | Receivables Acquired with Deteriorated Credit Quality [Member] | Real estate 1-4 family junior lien mortgage [Member]
By delinquency status:
PCI loans	2	2
120-179 DPD member [Member] | Receivables Acquired with Deteriorated Credit Quality [Member] | Residential Mortgage [Member]
By delinquency status:
PCI loans	157	240
180 plus DPD [Member] | Receivables Acquired with Deteriorated Credit Quality [Member] | Real estate 1-4 family first mortgage [Member]
By delinquency status:
PCI loans	1,606	2,081
180 plus DPD [Member] | Receivables Acquired with Deteriorated Credit Quality [Member] | Real estate 1-4 family junior lien mortgage [Member]
By delinquency status:
PCI loans	6	8
180 plus DPD [Member] | Receivables Acquired with Deteriorated Credit Quality [Member] | Residential Mortgage [Member]
By delinquency status:
PCI loans	$ 1,612	$ 2,089