Firm loan commitments and unused portion of lines of credit [Abstract]

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- Definition

Amount of investment in State of Iowa state and political subdivisions debt and equity securities categorized neither as held-to-maturity nor trading.

+ References

No definition available.

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- References

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- Definition

The fair value of financial liabilities, which are not recognized in the financial statements (off-balance sheet) because they fail to meet some other criterion for recognition.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 825
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 11
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482907/825-10-50-11

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 825
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 10
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482907/825-10-50-10

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- Definition

Federal Home Loan Bank (FHLB) stock represents an equity interest in a FHLB. It does not have a readily determinable fair value because its ownership is restricted and it lacks a market (liquidity).

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 942
-SubTopic 325
-Name Accounting Standards Codification
-Section 45
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477974/942-325-45-1

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- Definition

Amount of expected credit loss for credit exposure on off-balance-sheet commitment, including but not limited to, loan commitment, standby letter of credit, financial guarantee not accounted for as insurance. Excludes off-balance sheet credit exposure accounted for as insurance and instrument accounted for under derivatives and hedging.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 45
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479344/326-20-45-2

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 460
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482454/460-10-45-1

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Commitments and Contingencies (Details) - USD ($) $ in Thousands	Mar. 31, 2026	Dec. 31, 2025	Mar. 31, 2025	Dec. 31, 2024
Commitments and Contingencies Disclosure [Abstract]
Investment in securities issued by state and political subdivisions within the state of Iowa	$ 160,240		$ 153,880
Firm loan commitments and unused portion of lines of credit [Abstract]
Total financial instrument liabilities with off-balance-sheet risk	676,741	$ 686,436
Impact of adopting ASC 326	4,340	4,501	$ 3,700	$ 2,900
Stock of Federal Home Loan Bank	22,787	32,063
Home equity loans
Firm loan commitments and unused portion of lines of credit [Abstract]
Total financial instrument liabilities with off-balance-sheet risk	95,868	93,895
Credit cards
Firm loan commitments and unused portion of lines of credit [Abstract]
Total financial instrument liabilities with off-balance-sheet risk	80,677	80,910
Commercial, real estate and home construction
Firm loan commitments and unused portion of lines of credit [Abstract]
Total financial instrument liabilities with off-balance-sheet risk	188,869	177,797
Commercial lines and real estate purchase loans
Firm loan commitments and unused portion of lines of credit [Abstract]
Total financial instrument liabilities with off-balance-sheet risk	300,275	322,682
Outstanding letters of credit
Firm loan commitments and unused portion of lines of credit [Abstract]
Total financial instrument liabilities with off-balance-sheet risk	$ 11,052	$ 11,152