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		Mar. 31, 2016	Dec. 31, 2015
Servicing Assets at Fair Value [Line Items]
LHFS excluded from managed loans disclosure		$ 1,900	$ 1,800
Principal Amount Outstanding on Loans Managed and Securitized or Asset-backed Financing Arrangement	[1]	261,753	258,212
Loans Held For Sale [Member]
Servicing Assets at Fair Value [Line Items]
LHFS Accruing90OrMoreDaysPastDueAndNonaccruingExcludedFromManagedLoanDisclosure		1	0
Asset-backed Securities, Securitized Loans and Receivables [Member]
Servicing Assets at Fair Value [Line Items]
Principal Amount Outstanding on Loans Managed and Securitized or Asset-backed Financing Arrangement	[1]	118,263	117,797
Residential Portfolio Segment [Member] | Asset-backed Securities, Securitized Loans and Receivables [Member]
Servicing Assets at Fair Value [Line Items]
Principal Amount Outstanding on Loans Managed and Securitized or Asset-backed Financing Arrangement	[1]	117,534	116,990
Residential Portfolio Segment [Member] | Asset-backed Securities, Securitized Loans and Receivables [Member] | STI Sponsored Securitizations [Member]
Servicing Assets at Fair Value [Line Items]
Principal Amount Outstanding on Loans Managed and Securitized or Asset-backed Financing Arrangement	[1]	480	501
Residential Portfolio Segment [Member] | Asset-backed Securities, Securitized Loans and Receivables [Member] | Managed Securitized Loans [Member]
Servicing Assets at Fair Value [Line Items]
Principal Amount Outstanding on Loans Managed and Securitized or Asset-backed Financing Arrangement	[1]	$ 117,054	$ 116,489

[1] Excludes $1.9 billion and $1.8 billion of LHFS at March 31, 2016 and December 31, 2015, respectively.