Credit Quality (Summary of the ALLL and Related Loans and Leases Classified by Portfolio Segment) (Parenthetical) (Detail) - USD ($) $ in Millions	Mar. 31, 2019		Dec. 31, 2018		Mar. 31, 2018	Dec. 31, 2017
Financing Receivable, Allowance for Credit Losses
Allowance for loan and lease losses	$ 1,115	[1]	$ 1,103	[1]	$ 1,138	$ 1,196
Portfolio loans and leases	109,652		95,086
Residential Mortgage Loans
Financing Receivable, Allowance for Credit Losses
Loans measured at fair value on a recurring basis	190		179
Leveraged leases
Financing Receivable, Allowance for Credit Losses
Allowance for loan and lease losses	1		1
Portfolio loans and leases	$ 571		$ 624

[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 .