Composition of loans receivable and the allowance for loan losses (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Line Items]
Totals	$ 1,066,216	$ 1,066,750
Allowance For Loan And Lease Losses Collectively Evaluated Loans [Member]
SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Line Items]
Residential 1-4 family	379,269	370,558
Residential 5+ multifamily	53,291	51,376
Construction of residential 1-4 family	20,818	19,738
Home equity lines of credit	23,276	23,249
Residential real estate	476,654	464,921
Commercial	307,548	307,377
Construction of commercial	65,273	58,838
Commercial real estate	372,821	366,215
Farm land	2,358	2,375
Vacant land	14,710	14,182
Real estate secured	866,543	847,694
Commercial and industrial	177,394	194,856
Municipal	14,263	16,534
Consumer	14,356	12,547
Unallocated allowance
Totals	1,072,556	1,071,630
SEC Schedule, 12-09, Allowance, Loan and Lease Loss, Real Estate [Member]
SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Line Items]
Residential 1-4 family	3,063	2,845
Residential 5+ multifamily	820	817
Construction of residential 1-4 family	195	186
Home equity lines of credit	198	198
Residential real estate	4,276	4,046
Commercial	5,173	5,388
Construction of commercial	1,139	1,025
Commercial real estate	6,312	6,413
Farm land	19	21
Vacant land	110	95
Real estate secured	10,717	10,575
Commercial and industrial	1,173	1,297
Municipal	27	31
Consumer	105	82
Unallocated allowance	867	881
Totals	12,889	12,866
Allowance For Loan And Lease Losses Individually Evaluated Loans [Member]
SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Line Items]
Residential 1-4 family	1,938	2,573
Residential 5+ multifamily	85	949
Construction of residential 1-4 family
Home equity lines of credit		21
Residential real estate	2,023	3,543
Commercial	3,267	3,546
Construction of commercial
Commercial real estate	3,267	3,546
Farm land	420	432
Vacant land
Real estate secured	5,710	7,520
Commercial and industrial	104	276
Municipal
Consumer
Unallocated allowance
Totals	5,814	7,797
SEC Schedule, 12-09, Allowance, Loan and Lease Loss [Member]
SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Line Items]
Residential 1-4 family		1
Residential 5+ multifamily
Construction of residential 1-4 family
Home equity lines of credit
Residential real estate		1
Commercial	23	28
Construction of commercial
Commercial real estate	23	28
Farm land
Vacant land
Real estate secured	23	29
Commercial and industrial	3	67
Municipal
Consumer
Unallocated allowance
Totals	26	96
Allowance For Loan And Lease Losses Total Portfolio Loans [Member]
SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Line Items]
Residential 1-4 family	381,207	373,131
Residential 5+ multifamily	53,376	52,325
Construction of residential 1-4 family	20,818	19,738
Home equity lines of credit	23,276	23,270
Residential real estate	478,677	468,464
Commercial	310,815	310,923
Construction of commercial	65,273	58,838
Commercial real estate	376,088	369,761
Farm land	2,778	2,807
Vacant land	14,710	14,182
Real estate secured	872,253	855,214
Commercial and industrial	177,498	195,132
Municipal	14,263	16,534
Consumer	14,356	12,547
Unallocated allowance
Totals	1,078,370	1,079,427
Allowance For Loan And Lease Losses Total Portfolio Allowance [Member]
SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Line Items]
Residential 1-4 family	3,063	2,846
Residential 5+ multifamily	820	817
Construction of residential 1-4 family	195	186
Home equity lines of credit	198	198
Residential real estate	4,276	4,047
Commercial	5,196	5,416
Construction of commercial	1,139	1,025
Commercial real estate	6,335	6,441
Farm land	19	21
Vacant land	110	95
Real estate secured	10,740	10,604
Commercial and industrial	1,176	1,364
Municipal	27	31
Consumer	105	82
Unallocated allowance	867	881
Totals	$ 12,915	$ 12,962

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Amount of allowance for credit loss on receivable, classified as other and current.

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The fair value as of the balance sheet date of firm holdings in fixed income obligations issued by state and local governments and authorities. Includes both pledged (to counterparties as collateral for financing transactions) and unpledged holdings.

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The net carrying amount as of the balance sheet date of the sum of the various components of an operative builder's inventory, including finished homes. Operative builders primarily consist of entities that develop land, construct residential homes and commercial and industrial buildings thereon, and sell them to home buyers and operators of the commercial and industrial properties.

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Total of (1) improvements, (2) held-for-sale, (3) land and land under development, (4) construction-in-process, (5) mortgage loans held-in-inventory, and (6) other real estate investments which are considered inventory due to being held for sale or disposition.

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Cost of real estate projects incurred for projects for eventual sale or transfer (condominium or time share projects, vacation clubs).

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Carrying amount as of the balance sheet date, net of valuation allowances and impairment losses, of costs of land expected to be developed in the near term plus capitalized costs of development, for purposes of selling completed units to home buyers or commercial or industrial entities..

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Represents mortgage loans held in inventory primarily for sale to others (third parties, businesses, legal entities) in the ordinary course of business.

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Amount of investment in certain other real estate investments not specifically identified elsewhere in the existing taxonomy.

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Amount before allowance and after deduction of deferred interest and fees, unamortized costs and premiums and discounts from face amounts, of loans and leases held in portfolio, including but not limited to, commercial and consumer loans. Excludes loans and leases covered under loss sharing agreements.

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Amount after allowance and deduction of deferred interest and fees, unamortized costs and premiums and discounts from face amounts, of loans and leases held in portfolio, including but not limited to, commercial and consumer loans. Excludes loans and leases covered under loss sharing agreements and loans held for sale.

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The balance represents the amount of loans that are secured by real estate mortgages, offset by the reserve to cover probable credit losses on the loan portfolio.

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