Credit Quality (Summary of Transactions in the ALLL by Portfolio segment) (Detail) - USD ($) $ in Millions	3 Months Ended			9 Months Ended
	Sep. 30, 2017		Sep. 30, 2016	Sep. 30, 2017		Sep. 30, 2016
Financing Receivable, Allowance for Credit Losses
Balance, beginning of period	$ 1,226		$ 1,299	$ 1,253	[1],[2]	$ 1,272
Losses charged-off	(85)		(137)	(287)		(359)
Recoveries of losses previously charged- off	17		30	66		70
Provision for (benefit from) loan and lease losses	67		80	193		289
Deconsolidation of a VIE	(20)			(20)
Balance, end of period	1,205	[2],[3]	1,272	1,205	[2],[3]	1,272
Commercial Portfolio Segment
Financing Receivable, Allowance for Credit Losses
Balance, beginning of period	817		873	831	[1]	840
Losses charged-off	(33)		(81)	(119)		(192)
Recoveries of losses previously charged- off	3		18	25		29
Provision for (benefit from) loan and lease losses	9		44	59		177
Deconsolidation of a VIE	(19)			(19)
Balance, end of period	777	[3]	854	777	[3]	854
Residential Mortgage Loans
Financing Receivable, Allowance for Credit Losses
Balance, beginning of period	93		98	96	[1]	100
Losses charged-off	(2)		(4)	(12)		(14)
Recoveries of losses previously charged- off	3		2	7		7
Provision for (benefit from) loan and lease losses	(4)		0	(1)		3
Deconsolidation of a VIE	0			0
Balance, end of period	90	[3]	96	90	[3]	96
Consumer Portfolio Segment
Financing Receivable, Allowance for Credit Losses
Balance, beginning of period	206		211	214	[1]	217
Losses charged-off	(50)		(52)	(156)		(153)
Recoveries of losses previously charged- off	11		10	34		34
Provision for (benefit from) loan and lease losses	51		38	126		109
Deconsolidation of a VIE	0			0
Balance, end of period	218	[3]	207	218	[3]	207
Unallocated
Financing Receivable, Allowance for Credit Losses
Balance, beginning of period	110		117	112	[1]	115
Losses charged-off	0		0	0		0
Recoveries of losses previously charged- off	0		0	0		0
Provision for (benefit from) loan and lease losses	11		(2)	9		0
Deconsolidation of a VIE	(1)			(1)
Balance, end of period	$ 120	[3]	$ 115	$ 120	[3]	$ 115

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

[2] Includes $ 116 and $ 85 of cash and due from banks, $ 1,532 and $ 1,216 of portfolio loans and leases , $ (8) and $ (26) of ALLL, $ 9 and $ 9 of other assets, $ 3 and $ 3 of other liabilities , and $ 1,491 and $ 1,094 of long-term debt from consolidated VIEs that are included in their respective captions above at September 30, 2017 and December 31, 2016 , respectively. For further information refer to Note 11 .

[3] Includes $ 1 related to leveraged leases at September 30, 2017 .