Purchased Loans (Narrative) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013	Dec. 31, 2013
Financing Receivable, Impaired [Line Items]
Provision for credit losses (benefit)	$ 72	$ 157	$ 166	$ 393
Charge-offs			564	925
Specific allowance for loan and lease losses associated with purchased impaired loans	554		554		625
Purchased impaired loans	5,557	6,778	5,557	6,778	6,106
Purchased Impaired Loans [Member]
Financing Receivable, Impaired [Line Items]
Provision for credit losses (benefit)			(95)	90
Charge-offs			24	70
Specific allowance for loan and lease losses associated with purchased impaired loans	900		900		1,000
Purchased impaired loans	5,557		5,557		6,106
Impaired Loans With Associated Allowance [Member]
Financing Receivable, Impaired [Line Items]
Purchased impaired loans	4,900		4,900
Impaired Loans Without Associated Allowance [Member]
Financing Receivable, Impaired [Line Items]
Purchased impaired loans	$ 700		$ 700