Portfolio Balances and Delinquency Balances Based on 90 days or more Past Due and Net Charge-Offs Related to Managed Portfolio Loans (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012
Cash Flows Between Transferor and Transferee, Receipts on Transferor's Interest in Transferred Financial Assets, Other	$ 21		$ 36		$ 30
Principal Amount Outstanding on Loans Managed and Securitized or Asset-backed Financing Arrangement	243,703	[1]	230,189	[1]
Past Due	1,874	[2]	2,721	[2]
Net Credit Losses During Period on Loans Managed or Securitized or Asset-backed Financing Arrangement	461		701
Loans
Principal Balance	133,112	[1]	127,877	[1]
Past Due	1,691	[2]	2,199	[2]
Net Credit Losses During Period on Loans Managed or Securitized or Asset-backed Financing Arrangement	445		678
Commercial Portfolio Segment [Member] | Loans
Principal Balance	73,392	[1]	64,310	[1]
Past Due	181	[2]	272	[2]
Net Credit Losses During Period on Loans Managed or Securitized or Asset-backed Financing Arrangement	71		153
Commercial Portfolio Segment [Member] | Managed Securitized Loans
Past Due	0	[2]	29	[2]
Net Credit Losses During Period on Loans Managed or Securitized or Asset-backed Financing Arrangement	0		0
Continuing Involvement with Derecognized Transferred Financial Assets, Amount Outstanding	0	[1]	1,617	[1]
Residential Portfolio Segment [Member] | Loans
Principal Balance	38,775	[1]	43,190	[1]
Past Due	891	[2]	1,296	[2]
Net Credit Losses During Period on Loans Managed or Securitized or Asset-backed Financing Arrangement	279		444
Residential Portfolio Segment [Member] | Managed Securitized Loans
Past Due	183	[2],[3]	493	[2],[3]
Net Credit Losses During Period on Loans Managed or Securitized or Asset-backed Financing Arrangement	16		23
Continuing Involvement with Derecognized Transferred Financial Assets, Amount Outstanding	110,591	[1]	100,695	[1]
Consumer Portfolio Segment [Member] | Loans
Principal Balance	20,945	[1]	20,377	[1]
Past Due	619	[2]	631	[2]
Net Credit Losses During Period on Loans Managed or Securitized or Asset-backed Financing Arrangement	$ 95		$ 81

[1] Excludes $3.2 billion and $1.7 billion of LHFS at December 31, 2014 and 2013, respectively.

[2] Excludes $39 million and $17 million of past due LHFS at December 31, 2014 and 2013, respectively.

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