Loans and Leases - Schedule of Subsequently Defaulted TDRs (Detail) $ in Thousands	12 Months Ended
Dec. 31, 2019 USD ($) SecurityLoan	Dec. 31, 2018 USD ($) SecurityLoan	Dec. 31, 2017 USD ($) SecurityLoan
Accounts, Notes, Loans and Financing Receivable
Threshold period for loans in default (in days)	30 days
TDRs \| TDRs Occurring during the Period
Accounts, Notes, Loans and Financing Receivable
Number of Loans \| SecurityLoan	282	246	359
Pre-modification Outstanding Recorded Investment	$ 68,912	$ 66,395	$ 70,233
Post-modification Outstanding Recorded Investment		$ 53,171	$ 70,459
Number of loans \| SecurityLoan	117	81	163
Recorded investment	$ 19,609	$ 7,512	$ 28,734
TDRs \| Commercial Loans \| Real estate - construction \| TDRs Occurring during the Period
Accounts, Notes, Loans and Financing Receivable
Number of Loans \| SecurityLoan	2	3	4
Pre-modification Outstanding Recorded Investment	$ 6,377	$ 4,819	$ 9,404
Post-modification Outstanding Recorded Investment	$ 9,258	$ 3,830	$ 9,628
Number of loans \| SecurityLoan	0	0	2
Recorded investment	$ 0	$ 0	$ 3,572
TDRs \| Commercial Loans \| Real estate - owner-occupied \| TDRs Occurring during the Period
Accounts, Notes, Loans and Financing Receivable
Number of Loans \| SecurityLoan	11	14	11
Pre-modification Outstanding Recorded Investment	$ 10,081	$ 4,257	$ 5,779
Post-modification Outstanding Recorded Investment	$ 9,587	$ 3,912	$ 5,706
Number of loans \| SecurityLoan	6	2	6
Recorded investment	$ 4,357	$ 142	$ 4,668
TDRs \| Commercial Loans \| Real estate - non-owner-occupied \| TDRs Occurring during the Period
Accounts, Notes, Loans and Financing Receivable
Number of Loans \| SecurityLoan	27	20	19
Pre-modification Outstanding Recorded Investment	$ 9,264	$ 3,719	$ 11,974
Post-modification Outstanding Recorded Investment	$ 8,436	$ 3,428	$ 13,738
Number of loans \| SecurityLoan	9	5	13
Recorded investment	$ 4,215	$ 1,039	$ 8,060
TDRs \| Commercial Loans \| Commercial and industrial \| TDRs Occurring during the Period
Accounts, Notes, Loans and Financing Receivable
Number of Loans \| SecurityLoan	66	52	57
Pre-modification Outstanding Recorded Investment	$ 30,536	$ 39,796	$ 21,651
Post-modification Outstanding Recorded Investment	$ 18,803	$ 30,295	$ 20,883
Number of loans \| SecurityLoan	27	13	32
Recorded investment	$ 7,027	$ 3,757	$ 6,550
TDRs \| Residential mortgage loans \| Residential mortgage \| TDRs Occurring during the Period
Accounts, Notes, Loans and Financing Receivable
Number of Loans \| SecurityLoan	36	19	24
Pre-modification Outstanding Recorded Investment	$ 2,729	$ 1,706	$ 1,897
Post-modification Outstanding Recorded Investment	$ 2,511	$ 1,529	$ 1,771
Number of loans \| SecurityLoan	15	8	16
Recorded investment	$ 1,287	$ 773	$ 1,218
TDRs \| Consumer and Other Loans \| Consumer - home equity \| TDRs Occurring during the Period
Accounts, Notes, Loans and Financing Receivable
Number of Loans \| SecurityLoan	86	65	123
Pre-modification Outstanding Recorded Investment	$ 8,775	$ 10,607	$ 16,346
Post-modification Outstanding Recorded Investment	$ 8,262	$ 8,951	$ 15,862
Number of loans \| SecurityLoan	28	15	32
Recorded investment	$ 2,178	$ 1,354	$ 3,285
TDRs \| Consumer and Other Loans \| Consumer - other \| TDRs Occurring during the Period
Accounts, Notes, Loans and Financing Receivable
Number of Loans \| SecurityLoan	54	73	121
Pre-modification Outstanding Recorded Investment	$ 1,150	$ 1,491	$ 3,182
Post-modification Outstanding Recorded Investment	$ 1,018	$ 1,226	$ 2,871
Number of loans \| SecurityLoan	32	38	62
Recorded investment	$ 545	$ 447	$ 1,381

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Number of financing receivables that have been modified by troubled debt restructurings.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 33
-URI http://asc.fasb.org/extlink&oid=118936363&loc=SL6953676-111524

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+ 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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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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