Summary of Transactions in the ALLL by Portfolio segment (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2016		Mar. 31, 2015
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning Balance	$ 1,272	[1]	$ 1,322
Losses charged-off	(116)		(115)
Recoveries of losses previously charged- off	20		24
Provision for loan and lease losses	119		69
Ending Balance	1,295	[1]	1,300
Commercial Portfolio Segment
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning Balance	840	[2]	875
Losses charged-off	(60)		(48)
Recoveries of losses previously charged- off	6		9
Provision for loan and lease losses	81		16
Ending Balance	867	[3]	852
Residential Mortgage Loans
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning Balance	100	[2]	104
Losses charged-off	(4)		(9)
Recoveries of losses previously charged- off	2		3
Provision for loan and lease losses			5
Ending Balance	98	[3]	103
Consumer Portfolio Segment
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning Balance	217	[2]	237
Losses charged-off	(52)		(58)
Recoveries of losses previously charged- off	12		12
Provision for loan and lease losses	37		50
Ending Balance	214	[3]	241
Unallocated
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning Balance	115	[2]	106
Provision for loan and lease losses	1		(2)
Ending Balance	$ 116	[3]	$ 104

[1] Includes $147 and $152 of cash and due from banks, $2,178 and $2,537 of portfolio loans and leases, $(27) and $(28) of ALLL, $11 and $14 of other assets, $4 and $3 of other liabilities, and $2,102 and $2,487 of long-term debt from consolidated VIEs that are included in their respective captions above at March 31, 2016 and December 31, 2015, respectively. For further information refer to Note 9.

[2] Includes $5 related to leveraged leases at December 31, 2015.

[3] Includes $5 related to leveraged leases at March 31, 2016.