Summary of Transactions in the ALLL by Portfolio segment (Detail) (USD $) In Millions	3 Months Ended				9 Months Ended
	Sep. 30, 2011		Sep. 30, 2010		Sep. 30, 2011		Sep. 30, 2010
Beginning Balance	$ 2,614		$ 3,693		$ 3,004	[1]	$ 3,749
Losses charged off	(294)		(992)		(1,034)		(2,086)
Recoveries of losses previously charged off	32		36		101		114
Provision for loan and lease losses	87		457		368		1,372
Ending Balance	2,439	[1]	3,194	[1]	2,439	[1]	3,194	[1]
Commercial Portfolio Segment
Beginning Balance	1,764				1,989	[2]
Losses charged off	(146)				(480)
Recoveries of losses previously charged off	10				39
Provision for loan and lease losses	21				101
Ending Balance	1,649	[3]			1,649	[3]
Residential Mortgage Loans
Beginning Balance	268				310	[2]
Losses charged off	(38)				(142)
Recoveries of losses previously charged off	2				5
Provision for loan and lease losses	1				60
Ending Balance	233	[3]			233	[3]
Consumer Portfolio Segment
Beginning Balance	452				555	[2]
Losses charged off	(110)				(412)
Recoveries of losses previously charged off	20				57
Provision for loan and lease losses	46				208
Ending Balance	408	[3]			408	[3]
Unallocated (Member)
Beginning Balance	130				150	[2]
Provision for loan and lease losses	19				(1)
Ending Balance	$ 149	[3]			$ 149	[3]

[1] Includes $35, $52, and $56 of cash, $7, $7 and $7 of other short-term investments, $29, $29 and $29 of commercial mortgage loans, $228, $241 and $248 of home equity loans, $334, $648 and $771 of automobile loans, ($10), ($14) and ($15) of ALLL, $3, $7 and $7 of other assets, $5, $12 and $17 of other liabilities and $270, $692 and $834 of long-term debt from consolidated VIEs that are included in their respective captions above at September 30, 2011, December 31, 2010 and September 30, 2010, respectively. See Note 9.

[2] Includes $15 related to leveraged leases.

[3] Includes $14 related to leveraged leases