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	3 Months Ended			6 Months Ended
	Jun. 30, 2012		Jun. 30, 2011	Jun. 30, 2012		Jun. 30, 2011	Dec. 31, 2011
Principal Balance	$ 236,511			$ 236,511			$ 238,815
Past Due	7,270			7,270			8,284
Net Charge-offs	359		520	788		1,103
Loans
Principal Balance	124,560			124,560			122,495
Past Due	4,608			4,608			4,931
Net Charge-offs	350		505	772		1,076
Loans | Commercial Portfolio Segment [Member]
Principal Balance	57,814			57,814			55,872
Past Due	720			720			938
Net Charge-offs	63		179	164		335
Loans | Residential Portfolio Segment [Member]
Principal Balance	46,202			46,202			46,660
Past Due	2,935			2,935			3,079
Net Charge-offs	268		297	565		677
Loans | Consumer Portfolio Segment [Member]
Principal Balance	20,544			20,544			19,963
Past Due	953			953			914
Net Charge-offs	19		29	43		64
Managed Securitized Loans | Commercial Portfolio Segment [Member]
Principal Balance	1,920			1,920			1,978
Past Due	20			20			43
Net Charge-offs	0		0	0		0
Managed Securitized Loans | Residential Portfolio Segment [Member]
Principal Balance	110,031			110,031			114,342
Past Due	2,642	[1]		2,642	[1]		3,310	[1]
Net Charge-offs	$ 9		$ 15	$ 16		$ 27

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