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Leases - Additional Information (Detail)		3 Months Ended		9 Months Ended
	Jun. 11, 2024 USD ($) Property	Sep. 30, 2025 USD ($)	Sep. 30, 2024 USD ($)	Sep. 30, 2025 USD ($) Number	Sep. 30, 2024 USD ($)	Dec. 31, 2024 USD ($)
Lessee Lease Description [Line Items]
Loss on disposition of equipment					$ 2,522,000
Future lease payments		$ 9,185,000		$ 9,185,000
Finance lease liability		1,467,000		1,467,000		$ 1,509,000
Operating lease, Right-of-use asset		5,426,000		5,426,000		5,648,000
Operating lease liability		5,426,000		$ 5,426,000		$ 5,648,000
Branch Office and Certain Equipment Expires in June 2039
Lessee Lease Description [Line Items]
Lease expiration month and year				2039-06
Future lease payments		8,700,000		$ 8,700,000
Finance lease liability		1,500,000		1,500,000
Sale-leaseback transaction resulted pre-tax gain					2,500,000
Operating lease expense		164,000	$ 131,000	$ 528,000	160,000
Leased ATMs Expires in August 2030
Lessee Lease Description [Line Items]
Lease expiration month and year				2030-08
Future lease payments		374,000		$ 374,000
Operating lease expense		19,000	19,000	$ 57,000	57,000
Branch Office Expires in August 2027
Lessee Lease Description [Line Items]
Lease expiration month and year				2027-08
Future lease payments		83,000		$ 83,000
Operating lease expense		$ 10,000	$ 10,000	$ 30,000	$ 29,000
Real estate and equipment [Member] | Maximum [Member]
Lessee Lease Description [Line Items]
Operating leases remaining lease terms		15 years		15 years
Office and Branch [Member]
Lessee Lease Description [Line Items]
Aggregate cash purchase price	$ 7,500,000
Number of properties owned and operated | Property	4
Number of lease renewal | Number				1
Branch Office and Certain Equipment [Member]
Lessee Lease Description [Line Items]
Operating lease, renewal term		15 years		15 years
Operating lease initial term				15 years
Annual rent escalation percentage				2.50%

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Remaining lease term of operating lease, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

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