Loans and Allowance for Credit Losses, PCI, by FICO Score, Consumer (Details) - USD ($) $ in Millions	Jun. 30, 2017	Dec. 31, 2016
PCI Loans UPB [Member] | Real estate 1-4 family first mortgage [Member]
By FICO:
PCI loans	$ 18,312	$ 20,803
PCI Loans UPB [Member] | Real estate 1-4 family junior lien mortgage [Member]
By FICO:
PCI loans	175	192
PCI Loans UPB [Member] | Residential Mortgage [Member]
By FICO:
PCI loans	18,487	20,995
PCI Loans Carrying Value [Member]
By FICO:
PCI loans	14,273	16,731
PCI Loans Carrying Value [Member] | Real estate 1-4 family first mortgage [Member]
By FICO:
PCI loans	13,979	16,018
PCI Loans Carrying Value [Member] | Real estate 1-4 family junior lien mortgage [Member]
By FICO:
PCI loans	31	36
PCI Loans Carrying Value [Member] | Residential Mortgage [Member]
By FICO:
PCI loans	14,010	16,054
FICO less than 600 [Member] | Receivables Acquired with Deteriorated Credit Quality [Member] | Real estate 1-4 family first mortgage [Member]
By FICO:
PCI loans	4,450	4,292
FICO less than 600 [Member] | Receivables Acquired with Deteriorated Credit Quality [Member] | Real estate 1-4 family junior lien mortgage [Member]
By FICO:
PCI loans	42	46
FICO less than 600 [Member] | Receivables Acquired with Deteriorated Credit Quality [Member] | Residential Mortgage [Member]
By FICO:
PCI loans	4,492	4,338
FICO 600-639 [Member] | Receivables Acquired with Deteriorated Credit Quality [Member] | Real estate 1-4 family first mortgage [Member]
By FICO:
PCI loans	2,342	3,001
FICO 600-639 [Member] | Receivables Acquired with Deteriorated Credit Quality [Member] | Real estate 1-4 family junior lien mortgage [Member]
By FICO:
PCI loans	22	26
FICO 600-639 [Member] | Receivables Acquired with Deteriorated Credit Quality [Member] | Residential Mortgage [Member]
By FICO:
PCI loans	2,364	3,027
FICO 640-679 [Member] | Receivables Acquired with Deteriorated Credit Quality [Member] | Real estate 1-4 family first mortgage [Member]
By FICO:
PCI loans	2,599	3,972
FICO 640-679 [Member] | Receivables Acquired with Deteriorated Credit Quality [Member] | Real estate 1-4 family junior lien mortgage [Member]
By FICO:
PCI loans	30	35
FICO 640-679 [Member] | Receivables Acquired with Deteriorated Credit Quality [Member] | Residential Mortgage [Member]
By FICO:
PCI loans	2,629	4,007
FICO 680-719 [Member] | Receivables Acquired with Deteriorated Credit Quality [Member] | Real estate 1-4 family first mortgage [Member]
By FICO:
PCI loans	2,438	3,170
FICO 680-719 [Member] | Receivables Acquired with Deteriorated Credit Quality [Member] | Real estate 1-4 family junior lien mortgage [Member]
By FICO:
PCI loans	32	37
FICO 680-719 [Member] | Receivables Acquired with Deteriorated Credit Quality [Member] | Residential Mortgage [Member]
By FICO:
PCI loans	2,470	3,207
FICO 720-759 [Member] | Receivables Acquired with Deteriorated Credit Quality [Member] | Real estate 1-4 family first mortgage [Member]
By FICO:
PCI loans	1,845	1,767
FICO 720-759 [Member] | Receivables Acquired with Deteriorated Credit Quality [Member] | Real estate 1-4 family junior lien mortgage [Member]
By FICO:
PCI loans	25	24
FICO 720-759 [Member] | Receivables Acquired with Deteriorated Credit Quality [Member] | Residential Mortgage [Member]
By FICO:
PCI loans	1,870	1,791
FICO 760-799 [Member] | Receivables Acquired with Deteriorated Credit Quality [Member] | Real estate 1-4 family first mortgage [Member]
By FICO:
PCI loans	930	962
FICO 760-799 [Member] | Receivables Acquired with Deteriorated Credit Quality [Member] | Real estate 1-4 family junior lien mortgage [Member]
By FICO:
PCI loans	12	15
FICO 760-799 [Member] | Receivables Acquired with Deteriorated Credit Quality [Member] | Residential Mortgage [Member]
By FICO:
PCI loans	942	977
FICO 800 or more [Member] | Receivables Acquired with Deteriorated Credit Quality [Member] | Real estate 1-4 family first mortgage [Member]
By FICO:
PCI loans	446	254
FICO 800 or more [Member] | Receivables Acquired with Deteriorated Credit Quality [Member] | Real estate 1-4 family junior lien mortgage [Member]
By FICO:
PCI loans	6	4
FICO 800 or more [Member] | Receivables Acquired with Deteriorated Credit Quality [Member] | Residential Mortgage [Member]
By FICO:
PCI loans	452	258
No FICO available [Member] | Receivables Acquired with Deteriorated Credit Quality [Member] | Real estate 1-4 family first mortgage [Member]
By FICO:
PCI loans	3,262	3,385
No FICO available [Member] | Receivables Acquired with Deteriorated Credit Quality [Member] | Real estate 1-4 family junior lien mortgage [Member]
By FICO:
PCI loans	6	5
No FICO available [Member] | Receivables Acquired with Deteriorated Credit Quality [Member] | Residential Mortgage [Member]
By FICO:
PCI loans	$ 3,268	$ 3,390