Loans and Allowance for Credit Losses, Allowance for Credit Losses by Category (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Allowance for credit losses, beginning balance	$ 13,013	$ 14,414	$ 13,169	$ 14,971
Provision for credit losses	300	217	908	542
Interest income on certain impaired loans	(50)	(55)	(102)	(111)
Loan charge-offs	(1,041)	(1,161)	(2,137)	(2,445)
Loan recoveries	391	444	779	903
Net loan charge-offs	(650)	(717)	(1,358)	(1,542)
Allowance related to business combinations/other	1	(25)	(3)	(26)
Allowance for credit losses, ending balance	12,614	13,834	12,614	13,834
Commercial Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Allowance for credit losses, beginning balance	6,333	6,354	6,377	6,103
Provision for credit losses	11	83	20	346
Interest income on certain impaired loans	(4)	(6)	(9)	(12)
Loan charge-offs	(174)	(168)	(334)	(356)
Loan recoveries	112	137	228	320
Net loan charge-offs	(62)	(31)	(106)	(36)
Allowance related to business combinations/other	1	0	(3)	(1)
Allowance for credit losses, ending balance	6,279	6,400	6,279	6,400
Consumer Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Allowance for credit losses, beginning balance	6,680	8,060	6,792	8,868
Provision for credit losses	289	134	888	196
Interest income on certain impaired loans	(46)	(49)	(93)	(99)
Loan charge-offs	(867)	(993)	(1,803)	(2,089)
Loan recoveries	279	307	551	583
Net loan charge-offs	(588)	(686)	(1,252)	(1,506)
Allowance related to business combinations/other	0	(25)	0	(25)
Allowance for credit losses, ending balance	$ 6,335	$ 7,434	$ 6,335	$ 7,434