Certain Transfers of Financial Assets and Variable Interest Entities Portfolio Balances and Delinquency Balances Based on 90 days or more Past Due and Net Charge-Offs Related to Managed Portfolio Loans (Additional Information) (Details) - USD ($) $ in Millions	Dec. 31, 2015	Dec. 31, 2014
Servicing Assets at Fair Value [Line Items]
LHFS excluded from managed loans disclosure	$ 1,800	$ 3,200
Loans Held For Sale [Member]
Servicing Assets at Fair Value [Line Items]
LHFS Accruing90OrMoreDaysPastDueAndNonaccruingExcludedFromManagedLoanDisclosure	$ 1	$ 39