Credit Quality (Summary of Transactions in the ALLL by Portfolio segment) (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017		Mar. 31, 2016
Financing Receivable, Allowance for Credit Losses
Balance, beginning of period	$ 1,253	[1],[2]	$ 1,272
Losses charged-off	(107)		(116)
Recoveries of losses previously charged- off	18		20
Provision for (benefit from) loan and lease losses	74		119
Balance, end of period	1,238	[3]	1,295
Commercial Portfolio Segment
Financing Receivable, Allowance for Credit Losses
Balance, beginning of period	831	[1]	840
Losses charged-off	(46)		(60)
Recoveries of losses previously charged- off	4		6
Provision for (benefit from) loan and lease losses	37		81
Balance, end of period	826	[3]	867
Residential Mortgage Loans
Financing Receivable, Allowance for Credit Losses
Balance, beginning of period	96	[1]	100
Losses charged-off	(6)		(4)
Recoveries of losses previously charged- off	1		2
Provision for (benefit from) loan and lease losses	5		0
Balance, end of period	96	[3]	98
Consumer Portfolio Segment
Financing Receivable, Allowance for Credit Losses
Balance, beginning of period	214	[1]	217
Losses charged-off	(55)		(52)
Recoveries of losses previously charged- off	13		12
Provision for (benefit from) loan and lease losses	32		37
Balance, end of period	204	[3]	214
Unallocated
Financing Receivable, Allowance for Credit Losses
Balance, beginning of period	112	[1]	115
Losses charged-off	0		0
Recoveries of losses previously charged- off	0		0
Provision for (benefit from) loan and lease losses	0		1
Balance, end of period	$ 112	[3]	$ 116

[1] Includes $ 2 related to leveraged leases at December 31, 2016 .

[2] Includes $ 85 and $ 85 of cash and due from banks, $ 1,015 and $ 1,216 of portfolio loans and leases , $ (25) and $ (26) of ALLL, $ 7 and $ 9 of other assets, $ 2 and $ 3 of other liabilities , and $ 883 and $ 1,094 of long-term debt from consolidated VIEs that are included in their respective captions above at March 31, 2017 and December 31, 2016 , respectively. For further information refer to Note 10 .

[3] Includes $ 2 related to leveraged leases at March 31, 2017 .