Goodwill and Other Intangible Assets Intangible Assets Schedule of Future Amortization (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Amortization Expense, Next Twelve Months	$ 23
Finite-Lived Intangible Assets, Amortization Expense, Year Two	12
Finite-Lived Intangible Assets, Amortization Expense, Year Three	7
Finite-Lived Intangible Assets, Amortization Expense, Year Four	4
Finite-Lived Intangible Assets, Amortization Expense, Year Five	4
Finite-Lived Intangible Assets, Amortization Expense, after Year Five	7
Intangible Assets, Net (Excluding Goodwill)	956	1,017	1,571
Finite-Lived Intangible Assets, Net	57
Core Deposits [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Amortization Expense, Next Twelve Months	13
Finite-Lived Intangible Assets, Amortization Expense, Year Two	4
Finite-Lived Intangible Assets, Amortization Expense, Year Three	0
Finite-Lived Intangible Assets, Amortization Expense, Year Four	0
Finite-Lived Intangible Assets, Amortization Expense, Year Five	0
Finite-Lived Intangible Assets, Amortization Expense, after Year Five	0
Intangible Assets, Net (Excluding Goodwill)	17	38	67
Finite-Lived Intangible Assets, Net	17
Other Intangible Assets [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Amortization Expense, Next Twelve Months	10
Finite-Lived Intangible Assets, Amortization Expense, Year Two	8
Finite-Lived Intangible Assets, Amortization Expense, Year Three	7
Finite-Lived Intangible Assets, Amortization Expense, Year Four	4
Finite-Lived Intangible Assets, Amortization Expense, Year Five	4
Finite-Lived Intangible Assets, Amortization Expense, after Year Five	7
Intangible Assets, Net (Excluding Goodwill)	40	58	65
Finite-Lived Intangible Assets, Net	$ 40