Loans and Allowance for Credit Losses, Loans by FICO Score, Consumer (Details) - USD ($) $ in Millions	Jun. 30, 2015		Dec. 31, 2014	Dec. 31, 2008
By updated FICO:
Purchased Credit Impaired Loans (carrying value)	$ 21,555		$ 23,320
Loans	888,459	[1]	862,551
Total Consumer [Member]
By updated FICO:
Purchased Credit Impaired Loans (carrying value)	20,682		21,813	$ 40,100
Loans	450,437		447,725
Real estate 1-4 family first mortgage [Member]
By updated FICO:
Purchased Credit Impaired Loans (carrying value)	20,601		21,712
Loans	267,868		265,386
Real estate 1-4 family junior lien mortgage [Member]
By updated FICO:
Purchased Credit Impaired Loans (carrying value)	81		101
Loans	56,164		59,717
Credit Card [Member]
By updated FICO:
Purchased Credit Impaired Loans (carrying value)	0		0
Loans	31,135		31,119
Automobile [Member]
By updated FICO:
Purchased Credit Impaired Loans (carrying value)	0		0
Loans	57,801		55,740
Other revolving credit and installment [Member]
By updated FICO:
Purchased Credit Impaired Loans (carrying value)	0		0
Loans	37,469		35,763
Loans Excluding Purchased Credit-Impaired Loans [Member] | Total Consumer [Member]
By updated FICO:
Less than 600	26,026		27,525
600-639	20,354		20,542
640-679	35,727		35,867
680-719	54,082		54,050
720-759	67,888		67,439
760-799	125,316		120,242
800 and greater	62,719		61,561
No FICO available	7,218		6,564
FICO not required	6,536		5,854
Government insured/guaranteed loans	23,889		26,268
Loans, excluding Purchased Credit Impaired Loans	429,755		425,912
Loans Excluding Purchased Credit-Impaired Loans [Member] | Real estate 1-4 family first mortgage [Member]
By updated FICO:
Less than 600	10,143		11,166
600-639	7,570		7,866
640-679	13,765		13,894
680-719	24,460		24,412
720-759	36,085		35,490
760-799	87,575		82,123
800 and greater	40,323		39,219
No FICO available	3,457		3,236
FICO not required	0		0
Government insured/guaranteed loans	23,889		26,268
Loans, excluding Purchased Credit Impaired Loans	247,267		243,674
Loans Excluding Purchased Credit-Impaired Loans [Member] | Real estate 1-4 family junior lien mortgage [Member]
By updated FICO:
Less than 600	3,639		4,001
600-639	2,633		2,794
640-679	4,975		5,324
680-719	8,361		8,970
720-759	11,560		12,171
760-799	17,064		17,897
800 and greater	7,032		7,581
No FICO available	819		878
FICO not required	0		0
Government insured/guaranteed loans	0		0
Loans, excluding Purchased Credit Impaired Loans	56,083		59,616
Loans Excluding Purchased Credit-Impaired Loans [Member] | Credit Card [Member]
By updated FICO:
Less than 600	2,671		2,639
600-639	2,637		2,588
640-679	4,898		4,931
680-719	6,309		6,285
720-759	6,463		6,407
760-799	5,275		5,234
800 and greater	2,654		2,758
No FICO available	228		277
FICO not required	0		0
Government insured/guaranteed loans	0		0
Loans, excluding Purchased Credit Impaired Loans	31,135		31,119
Loans Excluding Purchased Credit-Impaired Loans [Member] | Automobile [Member]
By updated FICO:
Less than 600	8,637		8,825
600-639	6,467		6,236
640-679	9,781		9,352
680-719	10,668		9,994
720-759	7,949		7,475
760-799	7,468		7,315
800 and greater	6,424		6,184
No FICO available	407		359
FICO not required	0		0
Government insured/guaranteed loans	0		0
Loans, excluding Purchased Credit Impaired Loans	57,801		55,740
Loans Excluding Purchased Credit-Impaired Loans [Member] | Other revolving credit and installment [Member]
By updated FICO:
Less than 600	936		894
600-639	1,047		1,058
640-679	2,308		2,366
680-719	4,284		4,389
720-759	5,831		5,896
760-799	7,934		7,673
800 and greater	6,286		5,819
No FICO available	2,307		1,814
FICO not required	6,536		5,854
Government insured/guaranteed loans	0		0
Loans, excluding Purchased Credit Impaired Loans	$ 37,469		$ 35,763

[1] Parenthetical amounts represent assets and liabilities for which we have elected the fair value option.