Loan Sale and Servicing Activities and Variable Interest Entities (Principal Balance, Delinquent Loans (Loans 90 Days or More Past Due), and Net Charge-Offs Related to Serviced Loans) (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013
Quantifying Misstatement In Current Year Financial Statements Amount		$ 6,200,000,000
Residential Mortgages [Member]
Total principal balance	79,108,000,000	85,758,000,000
Delinquent loans	2,657,000,000	3,562,000,000
Net charge-offs	136,000,000	213,000,000
Commercial Mortgages [Member]
Total principal balance	60,873,000,000	62,872,000,000
Delinquent loans	707,000,000	2,353,000,000
Net charge-offs	1,288,000,000	916,000,000
Home Equity Loans Lines [Member]
Total principal balance	3,833,000,000	4,321,000,000
Delinquent loans	1,303,000,000	1,404,000,000
Net charge-offs	61,000,000	119,000,000
Quantifying Misstatement In Current Year Financial Statements Amount		$ 581,000,000