Credit Quality (Summary of Transactions in the ALLL by Portfolio segment) (Detail) - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2019		Mar. 31, 2018
Financing Receivable, Allowance for Credit Losses
Balance, beginning of period		$ 1,103	[1]	$ 1,196
Losses charged-off		(108)		(103)
Recoveries of losses previously charged- off		31		22
Provision for (benefit from) loan and lease losses		89		23
Balance, end of period		1,115	[1]	1,138
Commercial Portfolio Segment
Financing Receivable, Allowance for Credit Losses
Balance, beginning of period	[2]	645		753
Losses charged-off		(20)		(35)
Recoveries of losses previously charged- off		3		6
Provision for (benefit from) loan and lease losses		26		(11)
Balance, end of period		654	[3]	713
Residential Mortgage Loans
Financing Receivable, Allowance for Credit Losses
Balance, beginning of period	[2]	81		89
Losses charged-off		(2)		(4)
Recoveries of losses previously charged- off		1		1
Provision for (benefit from) loan and lease losses		(1)		3
Balance, end of period		79	[3]	89
Consumer Portfolio Segment
Financing Receivable, Allowance for Credit Losses
Balance, beginning of period	[2]	267		234
Losses charged-off		(86)		(64)
Recoveries of losses previously charged- off		27		15
Provision for (benefit from) loan and lease losses		62		37
Balance, end of period		270	[3]	222
Unallocated
Financing Receivable, Allowance for Credit Losses
Balance, beginning of period	[2]	110		120
Losses charged-off		0		0
Recoveries of losses previously charged- off		0		0
Provision for (benefit from) loan and lease losses		2		(6)
Balance, end of period		$ 112	[3]	$ 114

[1] Includes $ 39 and $ 40 of other short-term investments , $ 573 and $ 668 of portfolio loans and leases, $ (3) and $ (4) of ALLL, $ 3 and $ 5 of other assets, $ 1 and $ 1 of other liabilities, and $ 510 and $ 606 of long-term debt from consolidated VIEs that are included in their respe ctive captions above at March 31, 2019 and December 31, 2018 , respectively. For further information refer to Note 13 .

[2] Includes $ 1 related to leveraged leases at December 31, 2018 .

[3] Includes $ 1 related to leveraged leases at March 31, 2019 .