Allowance for Credit Losses (Summary of the Post-Modification Balance of Loans Restructured) (Detail) $ in Thousands	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2022 USD ($) contract	Jun. 30, 2021 USD ($) contract	Jun. 30, 2022 USD ($) contract	Jun. 30, 2021 USD ($) contract	Jun. 30, 2022 USD ($) contract	Jun. 30, 2021 USD ($) contract
Financing Receivable, Troubled Debt Restructuring [Line Items]
TDRs, count | contract	16	16	29	36	57	93
TDRs, balance | $	$ 2,421	$ 4,199	$ 5,518	$ 6,325	$ 13,061	$ 19,383
Extension at Below Market Terms
Financing Receivable, Troubled Debt Restructuring [Line Items]
TDRs, count | contract	16	15	27	35
TDRs, balance | $	$ 2,420	$ 3,656	$ 4,626	$ 5,782
Reduction of Interest Rate
Financing Receivable, Troubled Debt Restructuring [Line Items]
TDRs, count | contract	10	3	19	13
TDRs, balance | $	$ 1,805	$ 1,159	$ 3,830	$ 2,562
Modification to Interest-only Payments
Financing Receivable, Troubled Debt Restructuring [Line Items]
TDRs, count | contract	0	0	4	1
TDRs, balance | $	$ 0	$ 0	$ 2,154	$ 113
Forgiveness of Debt
Financing Receivable, Troubled Debt Restructuring [Line Items]
TDRs, count | contract	0	0	0	0
TDRs, balance | $	$ 0	$ 0	$ 0	$ 0
Commercial, industrial and other | Commercial, industrial and other
Financing Receivable, Troubled Debt Restructuring [Line Items]
TDRs, count | contract	2	3	5	5	16	14
TDRs, balance | $	$ 186	$ 395	$ 468	$ 546	$ 4,995	$ 3,875
Commercial, industrial and other | Commercial, industrial and other | Extension at Below Market Terms
Financing Receivable, Troubled Debt Restructuring [Line Items]
TDRs, count | contract	2	3	4	5
TDRs, balance | $	$ 185	$ 395	$ 305	$ 546
Commercial, industrial and other | Commercial, industrial and other | Reduction of Interest Rate
Financing Receivable, Troubled Debt Restructuring [Line Items]
TDRs, count | contract	0	0	1	0
TDRs, balance | $	$ 0	$ 0	$ 85	$ 0
Commercial, industrial and other | Commercial, industrial and other | Modification to Interest-only Payments
Financing Receivable, Troubled Debt Restructuring [Line Items]
TDRs, count | contract	0	0	2	0
TDRs, balance | $	$ 0	$ 0	$ 247	$ 0
Commercial, industrial and other | Commercial, industrial and other | Forgiveness of Debt
Financing Receivable, Troubled Debt Restructuring [Line Items]
TDRs, count | contract	0	0	0	0
TDRs, balance | $	$ 0	$ 0	$ 0	$ 0
Commercial real estate | Non-construction
Financing Receivable, Troubled Debt Restructuring [Line Items]
TDRs, count | contract	0	3	2	5	2	9
TDRs, balance | $	$ 0	$ 2,707	$ 1,907	$ 2,944	$ 1,907	$ 4,090
Commercial real estate | Non-construction | Extension at Below Market Terms
Financing Receivable, Troubled Debt Restructuring [Line Items]
TDRs, count | contract	0	2	1	4
TDRs, balance | $	$ 0	$ 2,164	$ 1,178	$ 2,401
Commercial real estate | Non-construction | Reduction of Interest Rate
Financing Receivable, Troubled Debt Restructuring [Line Items]
TDRs, count | contract	0	1	1	2
TDRs, balance | $	$ 0	$ 543	$ 1,178	$ 656
Commercial real estate | Non-construction | Modification to Interest-only Payments
Financing Receivable, Troubled Debt Restructuring [Line Items]
TDRs, count | contract	0	0	2	1
TDRs, balance | $	$ 0	$ 0	$ 1,907	$ 113
Commercial real estate | Non-construction | Forgiveness of Debt
Financing Receivable, Troubled Debt Restructuring [Line Items]
TDRs, count | contract	0	0	0	0
TDRs, balance | $	$ 0	$ 0	$ 0	$ 0
Residential real estate and other
Financing Receivable, Troubled Debt Restructuring [Line Items]
TDRs, count | contract	14	10	22	26	39	70
TDRs, balance | $	$ 2,235	$ 1,097	$ 3,143	$ 2,835	$ 6,159	$ 11,418
Residential real estate and other | Extension at Below Market Terms
Financing Receivable, Troubled Debt Restructuring [Line Items]
TDRs, count | contract	14	10	22	26
TDRs, balance | $	$ 2,235	$ 1,097	$ 3,143	$ 2,835
Residential real estate and other | Reduction of Interest Rate
Financing Receivable, Troubled Debt Restructuring [Line Items]
TDRs, count | contract	10	2	17	11
TDRs, balance | $	$ 1,805	$ 616	$ 2,567	$ 1,906
Residential real estate and other | Modification to Interest-only Payments
Financing Receivable, Troubled Debt Restructuring [Line Items]
TDRs, count | contract	0	0	0	0
TDRs, balance | $	$ 0	$ 0	$ 0	$ 0
Residential real estate and other | Forgiveness of Debt
Financing Receivable, Troubled Debt Restructuring [Line Items]
TDRs, count | contract	0	0	0	0
TDRs, balance | $	$ 0	$ 0	$ 0	$ 0