Loans and Allowance for Credit Losses, Loans by FICO Score, Consumer (Details) - USD ($) $ in Millions		Jun. 30, 2019	Dec. 31, 2018
By FICO:
Loans	[1]	$ 949,878	$ 953,110
Total Consumer [Member]
By FICO:
Loans		437,633	439,705
Residential mortgage [Member]
By FICO:
Loans		318,495	319,463
Real estate 1-4 family first mortgage [Member]
By FICO:
Loans		286,427	285,065
Real estate 1-4 family junior lien mortgage [Member]
By FICO:
Loans		32,068	34,398
Credit Card [Member]
By FICO:
Loans		38,820	39,025
Automobile [Member]
By FICO:
Loans		45,664	45,069
Other revolving credit and installment [Member]
By FICO:
Loans		34,654	36,148
Non-PCI [Member] | Total Consumer [Member]
By FICO:
Loans		436,459	434,700
Non-PCI [Member] | Residential mortgage [Member]
By FICO:
Loans		317,321	314,458
Non-PCI [Member] | Real estate 1-4 family first mortgage [Member]
By FICO:
Loans		285,268	280,077
Non-PCI [Member] | Real estate 1-4 family junior lien mortgage [Member]
By FICO:
Loans		32,053	34,381
Non-PCI [Member] | Credit Card [Member]
By FICO:
Loans		38,820	39,025
Non-PCI [Member] | Automobile [Member]
By FICO:
Loans		45,664	45,069
Non-PCI [Member] | Other revolving credit and installment [Member]
By FICO:
Loans		34,654	36,148
Non-PCI [Member] | Government insured/guaranteed [Member] | Total Consumer [Member]
By FICO:
Loans		11,374	12,932
Non-PCI [Member] | Government insured/guaranteed [Member] | Residential mortgage [Member]
By FICO:
Loans		11,374	12,932
Non-PCI [Member] | Government insured/guaranteed [Member] | Real estate 1-4 family first mortgage [Member]
By FICO:
Loans		11,374	12,932
Non-PCI [Member] | Government insured/guaranteed [Member] | Real estate 1-4 family junior lien mortgage [Member]
By FICO:
Loans		0	0
Non-PCI [Member] | Government insured/guaranteed [Member] | Credit Card [Member]
By FICO:
Loans		0	0
Non-PCI [Member] | Government insured/guaranteed [Member] | Automobile [Member]
By FICO:
Loans		0	0
Non-PCI [Member] | Government insured/guaranteed [Member] | Other revolving credit and installment [Member]
By FICO:
Loans		0	0
Non-PCI [Member] | FICO less than 600 [Member] | Total Consumer [Member]
By FICO:
Loans		15,049	16,787
Non-PCI [Member] | FICO less than 600 [Member] | Real estate 1-4 family first mortgage [Member]
By FICO:
Loans		3,539	4,273
Non-PCI [Member] | FICO less than 600 [Member] | Real estate 1-4 family junior lien mortgage [Member]
By FICO:
Loans		1,297	1,454
Non-PCI [Member] | FICO less than 600 [Member] | Credit Card [Member]
By FICO:
Loans		3,064	3,292
Non-PCI [Member] | FICO less than 600 [Member] | Automobile [Member]
By FICO:
Loans		6,442	7,071
Non-PCI [Member] | FICO less than 600 [Member] | Other revolving credit and installment [Member]
By FICO:
Loans		707	697
Non-PCI [Member] | FICO 600-639 [Member] | Total Consumer [Member]
By FICO:
Loans		11,301	11,901
Non-PCI [Member] | FICO 600-639 [Member] | Real estate 1-4 family first mortgage [Member]
By FICO:
Loans		2,559	2,974
Non-PCI [Member] | FICO 600-639 [Member] | Real estate 1-4 family junior lien mortgage [Member]
By FICO:
Loans		897	994
Non-PCI [Member] | FICO 600-639 [Member] | Credit Card [Member]
By FICO:
Loans		2,670	2,777
Non-PCI [Member] | FICO 600-639 [Member] | Automobile [Member]
By FICO:
Loans		4,498	4,431
Non-PCI [Member] | FICO 600-639 [Member] | Other revolving credit and installment [Member]
By FICO:
Loans		677	725
Non-PCI [Member] | FICO 640-679 [Member] | Total Consumer [Member]
By FICO:
Loans		21,452	22,219
Non-PCI [Member] | FICO 640-679 [Member] | Real estate 1-4 family first mortgage [Member]
By FICO:
Loans		5,276	5,810
Non-PCI [Member] | FICO 640-679 [Member] | Real estate 1-4 family junior lien mortgage [Member]
By FICO:
Loans		1,720	1,898
Non-PCI [Member] | FICO 640-679 [Member] | Credit Card [Member]
By FICO:
Loans		6,313	6,464
Non-PCI [Member] | FICO 640-679 [Member] | Automobile [Member]
By FICO:
Loans		6,386	6,225
Non-PCI [Member] | FICO 640-679 [Member] | Other revolving credit and installment [Member]
By FICO:
Loans		1,757	1,822
Non-PCI [Member] | FICO 680-719 [Member] | Total Consumer [Member]
By FICO:
Loans		36,691	37,659
Non-PCI [Member] | FICO 680-719 [Member] | Real estate 1-4 family first mortgage [Member]
By FICO:
Loans		12,898	13,568
Non-PCI [Member] | FICO 680-719 [Member] | Real estate 1-4 family junior lien mortgage [Member]
By FICO:
Loans		3,620	3,908
Non-PCI [Member] | FICO 680-719 [Member] | Credit Card [Member]
By FICO:
Loans		9,415	9,445
Non-PCI [Member] | FICO 680-719 [Member] | Automobile [Member]
By FICO:
Loans		7,475	7,354
Non-PCI [Member] | FICO 680-719 [Member] | Other revolving credit and installment [Member]
By FICO:
Loans		3,283	3,384
Non-PCI [Member] | FICO 720-759 [Member] | Total Consumer [Member]
By FICO:
Loans		51,991	51,778
Non-PCI [Member] | FICO 720-759 [Member] | Real estate 1-4 family first mortgage [Member]
By FICO:
Loans		27,807	27,258
Non-PCI [Member] | FICO 720-759 [Member] | Real estate 1-4 family junior lien mortgage [Member]
By FICO:
Loans		4,947	5,323
Non-PCI [Member] | FICO 720-759 [Member] | Credit Card [Member]
By FICO:
Loans		8,022	7,949
Non-PCI [Member] | FICO 720-759 [Member] | Automobile [Member]
By FICO:
Loans		7,051	6,853
Non-PCI [Member] | FICO 720-759 [Member] | Other revolving credit and installment [Member]
By FICO:
Loans		4,164	4,395
Non-PCI [Member] | FICO 760-799 [Member] | Total Consumer [Member]
By FICO:
Loans		83,570	80,004
Non-PCI [Member] | FICO 760-799 [Member] | Real estate 1-4 family first mortgage [Member]
By FICO:
Loans		61,007	57,193
Non-PCI [Member] | FICO 760-799 [Member] | Real estate 1-4 family junior lien mortgage [Member]
By FICO:
Loans		6,001	6,315
Non-PCI [Member] | FICO 760-799 [Member] | Credit Card [Member]
By FICO:
Loans		5,323	5,227
Non-PCI [Member] | FICO 760-799 [Member] | Automobile [Member]
By FICO:
Loans		6,240	5,947
Non-PCI [Member] | FICO 760-799 [Member] | Other revolving credit and installment [Member]
By FICO:
Loans		4,999	5,322
Non-PCI [Member] | FICO 800 or more [Member] | Total Consumer [Member]
By FICO:
Loans		188,749	183,959
Non-PCI [Member] | FICO 800 or more [Member] | Real estate 1-4 family first mortgage [Member]
By FICO:
Loans		157,049	151,465
Non-PCI [Member] | FICO 800 or more [Member] | Real estate 1-4 family junior lien mortgage [Member]
By FICO:
Loans		12,346	13,190
Non-PCI [Member] | FICO 800 or more [Member] | Credit Card [Member]
By FICO:
Loans		3,879	3,794
Non-PCI [Member] | FICO 800 or more [Member] | Automobile [Member]
By FICO:
Loans		7,464	7,099
Non-PCI [Member] | FICO 800 or more [Member] | Other revolving credit and installment [Member]
By FICO:
Loans		8,011	8,411
Non-PCI [Member] | No FICO available [Member] | Total Consumer [Member]
By FICO:
Loans		7,660	8,576
Non-PCI [Member] | No FICO available [Member] | Real estate 1-4 family first mortgage [Member]
By FICO:
Loans		3,759	4,604
Non-PCI [Member] | No FICO available [Member] | Real estate 1-4 family junior lien mortgage [Member]
By FICO:
Loans		1,225	1,299
Non-PCI [Member] | No FICO available [Member] | Credit Card [Member]
By FICO:
Loans		134	77
Non-PCI [Member] | No FICO available [Member] | Automobile [Member]
By FICO:
Loans		108	89
Non-PCI [Member] | No FICO available [Member] | Other revolving credit and installment [Member]
By FICO:
Loans		2,434	2,507
Non-PCI [Member] | FICO not required [Member] | Total Consumer [Member]
By FICO:
Loans		8,622	8,885
Non-PCI [Member] | FICO not required [Member] | Real estate 1-4 family first mortgage [Member]
By FICO:
Loans		0	0
Non-PCI [Member] | FICO not required [Member] | Real estate 1-4 family junior lien mortgage [Member]
By FICO:
Loans		0	0
Non-PCI [Member] | FICO not required [Member] | Credit Card [Member]
By FICO:
Loans		0	0
Non-PCI [Member] | FICO not required [Member] | Automobile [Member]
By FICO:
Loans		0	0
Non-PCI [Member] | FICO not required [Member] | Other revolving credit and installment [Member]
By FICO:
Loans		8,622	8,885
PCI [Member]
By FICO:
Loans		1,174	5,009
PCI loans		1,174	5,009
PCI [Member] | Total Consumer [Member]
By FICO:
Loans		1,174	5,005
PCI loans		1,174	5,005
PCI [Member] | Residential mortgage [Member]
By FICO:
PCI loans		1,174	5,005
PCI [Member] | Real estate 1-4 family first mortgage [Member]
By FICO:
PCI loans		1,159	4,988
PCI [Member] | Real estate 1-4 family junior lien mortgage [Member]
By FICO:
PCI loans		15	17
PCI [Member] | Credit Card [Member]
By FICO:
PCI loans		0	0
PCI [Member] | Automobile [Member]
By FICO:
PCI loans		0	0
PCI [Member] | Other revolving credit and installment [Member]
By FICO:
PCI loans		$ 0	$ 0
PCI [Member] | No FICO available [Member] | Total Consumer [Member]
By FICO:
Unpaid principal balance, percent of FICO score		16.00%	15.00%
PCI [Member] | FICO less than 680 [Member] | Total Consumer [Member]
By FICO:
Unpaid principal balance, percent of FICO score		44.00%	45.00%

[1] (1) Parenthetical amounts represent assets and liabilities that we are required to carry at fair value or have elected the fair value option.