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Investment Securities - Additional Information (Detail)	3 Months Ended		6 Months Ended
	Jun. 30, 2025 USD ($) investmentSecurity securityLoan	Jun. 30, 2024 USD ($)	Jun. 30, 2025 USD ($) investmentSecurity securityLoan	Jun. 30, 2024 USD ($)	Dec. 31, 2024 USD ($)
Investment Securities [Line Items]
Proceeds from the sale of investment securities	$ 700,000	$ 28,600,000	$ 30,700,000	$ 28,600,000
Gross realized losses from the sale of investment securities	4,000.0	$ 2,900,000	1,100,000	$ 2,900,000
Securities pledged as collateral	891,900,000		891,900,000		$ 716,000,000.0
Residential real estate mortgage-backed securities	1,200,000,000		$ 1,200,000,000
Life of mortgage-backed securities			6 years 4 months 6 days
Allowance for credit loss	0		$ 0		$ 0
Obligations of U.S. government agencies
Investment Securities [Line Items]
Impairment losses recognized	0		0
Allowance for credit losses	$ 0		$ 0
Number of available for sale securities in unrealized loss position (in investment securities) | investmentSecurity	228		228
Percentage of aggregate depreciation in unrealized losses	(11.34%)		(11.34%)
Obligations of states and political subdivisions
Investment Securities [Line Items]
Impairment losses recognized	$ 0		$ 0
Allowance for credit losses	$ 0		$ 0
Number of available for sale securities in unrealized loss position (in investment securities) | investmentSecurity	153		153
Percentage of aggregate depreciation in unrealized losses	(11.83%)		(11.83%)
Corporate bonds
Investment Securities [Line Items]
Impairment losses recognized	$ 0		$ 0
Allowance for credit losses	$ 0		$ 0
Number of available for sale securities in unrealized loss position (in investment securities) | investmentSecurity	4		4
Percentage of aggregate depreciation in unrealized losses	(4.30%)		(4.30%)
Asset backed securities
Investment Securities [Line Items]
Impairment losses recognized	$ 0		$ 0
Allowance for credit losses	$ 0		$ 0
Number of available for sale securities in unrealized loss position (in investment securities) | investmentSecurity	23		23
Percentage of aggregate depreciation in unrealized losses	(1.59%)		(1.59%)
Non-agency collateralized mortgage obligations
Investment Securities [Line Items]
Allowance for credit losses	$ 0		$ 0
Number of available for sale securities in unrealized loss position (in investment securities) | securityLoan	17		17
Percentage of aggregate depreciation in unrealized losses	(10.03%)		(10.03%)

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