Loans and Leases - Schedule of Modified TDRs (Detail) - TDRs Occurring during the Period - TDRs $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2019 USD ($) SecurityLoan	Jun. 30, 2018 USD ($) SecurityLoan	Jun. 30, 2019 USD ($) SecurityLoan	Jun. 30, 2018 USD ($) SecurityLoan
Financing Receivable, Modifications
Number of Loans \| SecurityLoan	82	87	182	145
Pre-modification Outstanding Recorded Investment	$ 20,999	$ 27,761	$ 46,932	$ 58,105
Recorded investment	$ 12,023	$ 5,482	$ 14,923	$ 22,694
Number of loans \| SecurityLoan	96	61	138	126
Extended maturities	$ 7,633	$ 1,790	$ 11,175	$ 7,193
Maturity and interest rate adjustment	224	0	617	102
Movement to or extension of interest-rate only payments	1,771	1,316	1,783	1,364
Interest rate adjustment	74	0	74	103
Financing Receivable Modifications Forbearance	0	1,405	5,742	13,936
Other concession(s)	10,950	15,597	18,018	23,993
TDRs during period	20,652	20,108	$ 37,409	$ 46,691
Commercial Loans \| Real estate - construction
Financing Receivable, Modifications
Number of Loans \| SecurityLoan			1	1
Pre-modification Outstanding Recorded Investment			$ 39	$ 1,950
Recorded investment	$ 37	$ 0	$ 37	$ 0
Number of loans \| SecurityLoan	1	0	1	0
TDRs during period			$ 37	$ 1,013
Commercial Loans \| Real estate - owner-occupied
Financing Receivable, Modifications
Number of Loans \| SecurityLoan	4	5	6	7
Pre-modification Outstanding Recorded Investment	$ 339	$ 2,230	$ 1,435	$ 12,921
Recorded investment	$ 1,232	$ 461	$ 1,232	$ 9,455
Number of loans \| SecurityLoan	4	5	6	6
TDRs during period	$ 338	$ 2,201	$ 1,402	$ 11,290
Commercial Loans \| Real estate - non-owner-occupied
Financing Receivable, Modifications
Number of Loans \| SecurityLoan	7	5	13	14
Pre-modification Outstanding Recorded Investment	$ 4,687	$ 823	$ 7,756	$ 1,912
Recorded investment	$ 2,341	$ 1,448	$ 2,913	$ 1,813
Number of loans \| SecurityLoan	11	9	17	15
TDRs during period	$ 4,628	$ 780	$ 7,651	$ 1,854
Commercial Loans \| Commercial and industrial
Financing Receivable, Modifications
Number of Loans \| SecurityLoan	19	16	38	32
Pre-modification Outstanding Recorded Investment	$ 13,757	$ 21,103	$ 29,785	$ 35,338
Recorded investment	$ 5,475	$ 1,437	$ 6,152	$ 7,100
Number of loans \| SecurityLoan	17	8	25	21
TDRs during period	$ 13,607	$ 13,618	$ 20,670	$ 26,684
Residential mortgage loans \| Residential mortgage
Financing Receivable, Modifications
Number of Loans \| SecurityLoan	10	7	19	7
Pre-modification Outstanding Recorded Investment	$ 847	$ 688	$ 1,687	$ 688
Recorded investment	$ 1,012	$ 775	$ 1,597	$ 1,081
Number of loans \| SecurityLoan	12	7	21	10
TDRs during period	$ 836	$ 633	$ 1,669	$ 633
Consumer and Other Loans \| Consumer - Home equity
Financing Receivable, Modifications
Number of Loans \| SecurityLoan	22	19	54	33
Pre-modification Outstanding Recorded Investment	$ 1,159	$ 2,361	$ 5,312	$ 4,170
Recorded investment	$ 1,411	$ 1,129	$ 2,401	$ 2,242
Number of loans \| SecurityLoan	17	11	27	26
TDRs during period	$ 1,056	$ 2,350	$ 5,137	$ 4,133
Consumer and Other Loans \| Consumer - Other
Financing Receivable, Modifications
Number of Loans \| SecurityLoan	20	35	51	51
Pre-modification Outstanding Recorded Investment	$ 210	$ 556	$ 918	$ 1,126
Recorded investment	$ 515	$ 232	$ 591	$ 1,003
Number of loans \| SecurityLoan	34	21	41	48
TDRs during period	$ 187	$ 526	$ 843	$ 1,084

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Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
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-Name Accounting Standards Codification
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