Goodwill and Other Intangible Assets (Commercial and Residential Mortgage Loan Servicing Assets - Key Valuation Assumptions) (Details) (Servicing Contracts [Member], USD $) In Millions, unless otherwise specified	9 Months Ended	12 Months Ended
	Sep. 30, 2014	Dec. 31, 2013
Commercial Mortgage [Member]
Sensitivity Analysis Of Fair Value Of Interests Continued To Be Held By Transferor Servicing Assets Or Liabilities Impact Of Adverse Change In Assumption [Line Items]
Fair Value	$ 532	$ 552
Weighted-average life	5 years 0 months	5 years 4 months
Weighted-average constant prepayment rate	9.23%	7.52%
Decline in fair value from 10% adverse change in prepayment rate	11	12
Decline in fair value from 20% adverse change in prepayment rate	21	23
Effective discount rate	6.67%	6.91%
Decline in fair value from 10% adverse change in interest rate	15	18
Decline in fair value from 20% adverse change in interest rate	30	35
Residential Mortgage [Member]
Sensitivity Analysis Of Fair Value Of Interests Continued To Be Held By Transferor Servicing Assets Or Liabilities Impact Of Adverse Change In Assumption [Line Items]
Fair Value	978	1,087
Weighted-average life	7 years 0 months	7 years 11 months
Weighted-average constant prepayment rate	9.09%	7.61%
Decline in fair value from 10% adverse change in prepayment rate	36	34
Decline in fair value from 20% adverse change in prepayment rate	69	67
Weighted-average option adjusted spread	10.37%	10.24%
Decline in fair value from 10% adverse change in adjusted spread	39	47
Decline in fair value from 20% adverse change in adjusted spread	$ 75	$ 91