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, 2016	Dec. 31, 2015
Statement [Line Items]
Principal Amount Outstanding on Loans Managed and Securitized or Asset-backed Financing Arrangement		$ 278,197	$ 258,212
Loans Held For Sale [Member]
Statement [Line Items]
LHFS Accruing90OrMoreDaysPastDueAndNonaccruingExcludedFromManagedLoanDisclosure			1
Asset-backed Securities, Securitized Loans and Receivables [Member]
Statement [Line Items]
Principal Amount Outstanding on Loans Managed and Securitized or Asset-backed Financing Arrangement	[1]	131,914	117,797
Residential Portfolio Segment [Member] | Asset-backed Securities, Securitized Loans and Receivables [Member]
Statement [Line Items]
Principal Amount Outstanding on Loans Managed and Securitized or Asset-backed Financing Arrangement	[1]	126,641	116,990
Residential Portfolio Segment [Member] | Asset-backed Securities, Securitized Loans and Receivables [Member] | STI Sponsored Securitizations [Member]
Statement [Line Items]
Principal Amount Outstanding on Loans Managed and Securitized or Asset-backed Financing Arrangement		410	501
Residential Portfolio Segment [Member] | Asset-backed Securities, Securitized Loans and Receivables [Member] | Managed Securitized Loans [Member]
Statement [Line Items]
Principal Amount Outstanding on Loans Managed and Securitized or Asset-backed Financing Arrangement		126,231	116,489
Commercial Portfolio Segment [Member] | Asset-backed Securities, Securitized Loans and Receivables [Member]
Statement [Line Items]
Principal Amount Outstanding on Loans Managed and Securitized or Asset-backed Financing Arrangement	[1],[2]	$ 4,761	$ 0

[1] Excludes loans that have completed the foreclosure or short sale process (i.e., involuntary prepayments)

[2] Comprised of commercial mortgages sold by Pillar through Fannie Mae, Freddie Mac, and Ginnie Mae securitizations, whereby servicing has been retained by the Company.