Summary of Transactions in the ALLL by Portfolio segment (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended			6 Months Ended
	Jun. 30, 2014		Jun. 30, 2013	Jun. 30, 2014		Jun. 30, 2013
Beginning Balance	$ 1,483		$ 1,783	$ 1,582	[1]	$ 1,854
Losses charged off	(127)		(145)	(318)		(313)
Recoveries of losses previously charged off	26		33	48		68
Provision for loan and lease losses	76		64	146		126
Ending Balance	1,458	[1]	1,735	1,458	[1]	1,735
Commercial Portfolio Segment
Beginning Balance	981		1,191	1,058	[2]	1,236
Losses charged off	(55)		(59)	(164)		(128)
Recoveries of losses previously charged off	7		14	13		29
Provision for loan and lease losses	28		37	54		46
Ending Balance	961	[3]	1,183	961	[3]	1,183
Residential Mortgage Loans
Beginning Balance	180		212	189	[2]	229
Losses charged off	(11)		(18)	(30)		(40)
Recoveries of losses previously charged off	3		3	7		5
Provision for loan and lease losses	2		4	8		7
Ending Balance	174	[3]	201	174	[3]	201
Consumer Portfolio Segment
Beginning Balance	217		272	225	[2]	278
Losses charged off	(61)		(68)	(124)		(145)
Recoveries of losses previously charged off	16		16	28		34
Provision for loan and lease losses	49		27	92		80
Ending Balance	221	[3]	247	221	[3]	247
Unallocated
Beginning Balance	105		108	110	[2]	111
Provision for loan and lease losses	(3)		(4)	(8)		(7)
Ending Balance	$ 102	[3]	$ 104	$ 102	[3]	$ 104

[1] Includes $158 and $49 of cash and due from banks, $48 and $48 of commercial mortgage loans, $3,200 and $1,010 of automobile loans, $(20) and $(15) of ALLL, $32 and $13 of other assets, $6 and $1 of other liabilities, and $3,333 and $1,048 of long-term debt from consolidated VIEs that are included in their respective captions above at June 30, 2014 and December 31, 2013, respectively. See Note 9.

[2] Includes $9 related to leveraged leases.

[3] Includes $7 related to leveraged leases.