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		3 Months Ended		9 Months Ended
		Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014	Dec. 31, 2014
Principal Amount Outstanding on Loans Managed and Securitized or Asset-backed Financing Arrangement	[1]	$ 256,461		$ 256,461		$ 248,646
Delinquent Amount at End of Period on Loans Managed and Securitized or Asset-backed Financing Arrangement	[2]	2,091		2,091		2,579
Net Credit Losses During Period on Loans Managed or Securitized or Asset-backed Financing Arrangement		76	$ 134	269	$ 364
Commercial Portfolio Segment [Member]
Principal Balance	[1]	73,302		73,302		73,392
Delinquent Amount at End of Period on Loans Managed and Securitized or Asset-backed Financing Arrangement	[2]	151		151		181
Net Credit Losses During Period on Loans Managed or Securitized or Asset-backed Financing Arrangement		13	12	47	57
Residential Portfolio Segment [Member]
Principal Balance	[1]	38,788		38,788		38,775
Delinquent Amount at End of Period on Loans Managed and Securitized or Asset-backed Financing Arrangement	[2]	703		703		891
Net Credit Losses During Period on Loans Managed or Securitized or Asset-backed Financing Arrangement		36	92	146	227
Consumer Portfolio Segment [Member]
Principal Balance	[1]	21,470		21,470		20,945
Delinquent Amount at End of Period on Loans Managed and Securitized or Asset-backed Financing Arrangement	[2]	514		514		619
Net Credit Losses During Period on Loans Managed or Securitized or Asset-backed Financing Arrangement		22	24	65	67
Loans and Finance Receivables [Member]
Principal Balance	[1]	133,560		133,560		133,112
Delinquent Amount at End of Period on Loans Managed and Securitized or Asset-backed Financing Arrangement	[2]	1,368		1,368		1,691
Net Credit Losses During Period on Loans Managed or Securitized or Asset-backed Financing Arrangement		71	128	258	351
Asset-backed Securities, Securitized Loans and Receivables [Member]
Principal Amount Outstanding on Loans Managed and Securitized or Asset-backed Financing Arrangement	[1]	118,663		118,663		110,591
Delinquent Amount at End of Period on Loans Managed and Securitized or Asset-backed Financing Arrangement	[2],[3]	136		136		183
Net Credit Losses During Period on Loans Managed or Securitized or Asset-backed Financing Arrangement		5	6	11	13
Loans [Member]
Principal Amount Outstanding on Loans Managed and Securitized or Asset-backed Financing Arrangement	[1]	4,238		4,238		4,943
Delinquent Amount at End of Period on Loans Managed and Securitized or Asset-backed Financing Arrangement	[2]	587		587		705
Net Credit Losses During Period on Loans Managed or Securitized or Asset-backed Financing Arrangement		0	0	0	0
Consumer Portfolio Segment [Member] | Asset-backed Securities, Securitized Loans and Receivables [Member]
Principal Amount Outstanding on Loans Managed and Securitized or Asset-backed Financing Arrangement	[1]	889		889		0
Delinquent Amount at End of Period on Loans Managed and Securitized or Asset-backed Financing Arrangement	[2]	1		1		0
Net Credit Losses During Period on Loans Managed or Securitized or Asset-backed Financing Arrangement		1	0	1	0
Residential Portfolio Segment [Member] | Asset-backed Securities, Securitized Loans and Receivables [Member]
Principal Amount Outstanding on Loans Managed and Securitized or Asset-backed Financing Arrangement	[1]	117,774		117,774		110,591
Delinquent Amount at End of Period on Loans Managed and Securitized or Asset-backed Financing Arrangement	[2],[3]	135		135		$ 183
Net Credit Losses During Period on Loans Managed or Securitized or Asset-backed Financing Arrangement		$ 4	$ 6	$ 10	$ 13

[1] Excludes $2.0 billion and $3.2 billion of LHFS at September 30, 2015 and December 31, 2014, respectively.

[2] Excludes $1 million and $39 million of past due LHFS at September 30, 2015 and December 31, 2014, respectively.

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