Summary of Transactions in the ALLL by Portfolio segment (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013		Dec. 31, 2012		Dec. 31, 2011
Beginning Balance	$ 1,854	[1]	$ 2,255		$ 3,004
Losses charged off	(637)		(837)		(1,314)
Recoveries of losses previously charged off	136		133		142
Provision For Loan Lease And Other Losses	229		303		423
Ending Balance	1,582	[1]	1,854	[1]	2,255
Commercial Portfolio Segment
Beginning Balance	1,236		1,527		1,989
Losses charged off	(284)		(358)		(615)
Recoveries of losses previously charged off	64		61		61
Provision For Loan Lease And Other Losses	42		6		92
Ending Balance	1,058		1,236		1,527
Residential Mortgage Loans
Beginning Balance	229		227		310
Losses charged off	(70)		(129)		(180)
Recoveries of losses previously charged off	10		7		7
Provision For Loan Lease And Other Losses	20		124		90
Ending Balance	189		229		227
Consumer Portfolio Segment
Beginning Balance	278		365		555
Losses charged off	(283)		(350)		(519)
Recoveries of losses previously charged off	62		65		74
Provision For Loan Lease And Other Losses	168		198		255
Ending Balance	225		278		365
Unallocated
Beginning Balance	111		136		150
Provision For Loan Lease And Other Losses	(1)		(25)		(14)
Ending Balance	$ 110		$ 111		$ 136

[1] At December 31, 2013 and 2012, includes $49 and $0 of cash and due from banks, $48 and $50 of commercial mortgage loans, $ 1,010 and $0 of automobile loans, $(15) and $(5) of ALLL, $13 and $3 of other assets, $1 and $0 of other liabilities, $ 1,048 and $0 of long-term debt from consolidated VIEs that are included in their respective captions. See Note 10.