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, 2012		Dec. 31, 2011
Principal Balance	$ 228,114	[1]	$ 238,815	[1]
Past Due	4,538	[2]	8,284	[2]
Net Charge-offs	1,711		2,090
Loans
Principal Balance	121,470	[1]	122,495	[1]
Past Due	2,329	[2]	4,931	[2]
Net Charge-offs	1,681		2,040
Loans | Commercial Portfolio Segment [Member]
Principal Balance	58,888	[1]	55,872	[1]
Past Due	320	[2]	938	[2]
Net Charge-offs	303		663
Loans | Residential Portfolio Segment [Member]
Principal Balance	43,199	[1]	46,660	[1]
Past Due	1,941	[2]	3,079	[2]
Net Charge-offs	1,285		1,257
Loans | Consumer Portfolio Segment [Member]
Principal Balance	19,383	[1]	19,963	[1]
Past Due	68	[2]	914	[2]
Net Charge-offs	93		120
Managed Securitized Loans | Commercial Portfolio Segment [Member]
Principal Balance	1,767	[1]	1,978	[1]
Past Due	23	[2]	43	[2]
Net Charge-offs	0		0
Managed Securitized Loans | Residential Portfolio Segment [Member]
Principal Balance	104,877	[1]	114,342	[1]
Past Due	2,186	[2],[3]	3,310	[2],[3]
Net Charge-offs	$ 30		$ 50

[1] Excludes $3,399 million and $2,353 million of loans held for sale at December 31, 2012 and 2011, respectively.

[2] Excludes $38 million and $3 million of past due loans held for sale at December 31, 2012 and 2011, respectively.

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