Loans and Leases - Summary of Originated Troubled Debt Restructurings by Class of Loans and Leases, Payment Default (Detail) $ in Millions	12 Months Ended
Dec. 31, 2019 USD ($) Contract	Dec. 31, 2018 USD ($) Contract
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Contracts \| Contract	14	18
Recorded Investment \| $	$ 1	$ 2
Total commercial loans and leases
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Contracts \| Contract	6	4
Recorded Investment \| $	$ 1	$ 1
Commercial real estate
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Contracts \| Contract	5	3
Recorded Investment \| $	$ 1	$ 1
Commercial and industrial
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Contracts \| Contract	1	1
Recorded Investment \| $	$ 0	$ 0
Total consumer loans
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Contracts \| Contract	8	14
Recorded Investment \| $	$ 0	$ 1
Direct installment
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Contracts \| Contract	5	7
Recorded Investment \| $	$ 0	$ 1
Residential mortgages
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Contracts \| Contract	2	4
Recorded Investment \| $	$ 0	$ 0
Consumer lines of credit
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Contracts \| Contract	1	3
Recorded Investment \| $	$ 0	$ 0

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Number of financing receivable contracts modified as troubled debt restructuring within previous 12 months, with subsequent payment default.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 34
-URI http://asc.fasb.org/extlink&oid=118936363&loc=SL6953682-111524

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- Definition

Amount of financing receivable modified as troubled debt restructuring within previous 12 months, with subsequent payment default.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 34
-Subparagraph (a)(2)
-URI http://asc.fasb.org/extlink&oid=118936363&loc=SL6953682-111524

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