Summary of Transactions in the ALLL by Portfolio segment (Detail) - USD ($) $ in Millions	3 Months Ended			6 Months Ended
	Jun. 30, 2015		Jun. 30, 2014	Jun. 30, 2015		Jun. 30, 2014
Financing Receivable, Allowance for Credit Losses
Beginning Balance	$ 1,300		$ 1,483	$ 1,322	[1]	$ 1,582
Losses charged-off	(112)		(127)	(227)		(318)
Recoveries of losses previously charged- off	26		26	50		48
Provision for loan and lease losses	79		76	148		146
Ending Balance	1,293	[1]	1,458	1,293	[1]	1,458
Commercial Portfolio Segment
Financing Receivable, Allowance for Credit Losses
Beginning Balance	852		981	875	[2]	1,058
Losses charged-off	(54)		(55)	(102)		(164)
Recoveries of losses previously charged- off	9		7	18		13
Provision for loan and lease losses	48		28	64		54
Ending Balance	855	[3]	961	855	[3]	961
Residential Mortgage Loans
Financing Receivable, Allowance for Credit Losses
Beginning Balance	103		180	104	[2]	189
Losses charged-off	(8)		(11)	(17)		(30)
Recoveries of losses previously charged- off	3		3	6		7
Provision for loan and lease losses	6		2	11		8
Ending Balance	104	[3]	174	104	[3]	174
Consumer Portfolio Segment
Financing Receivable, Allowance for Credit Losses
Beginning Balance	241		217	237	[2]	225
Losses charged-off	(50)		(61)	(108)		(124)
Recoveries of losses previously charged- off	14		16	26		28
Provision for loan and lease losses	26		49	76		92
Ending Balance	231	[3]	221	231	[3]	221
Unallocated
Financing Receivable, Allowance for Credit Losses
Beginning Balance	104		105	106	[2]	110
Provision for loan and lease losses	(1)		(3)	(3)		(8)
Ending Balance	$ 103	[3]	$ 102	$ 103	[3]	$ 102

[1] Includes $156 and $179 of cash and due from banks, $2,547 and $3,378 of portfolio loans and leases, $(29) and $(22) of ALLL, $23 and $25 of other assets, $4 and $5 of other liabilities, and $2,542 and $3,434 of long-term debt from consolidated VIEs that are included in their respective captions above at June 30, 2015 and December 31, 2014, respectively. For further information refer to Note 10.

[2] Includes $6 related to leveraged leases.

[3] Includes $5 related to leveraged leases.