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Note 5 - Deposits (Details Textual) - USD ($) $ in Millions	Mar. 31, 2026	Dec. 31, 2025
Time Deposits, at or Above FDIC Insurance Limit	$ 173.4	$ 164.2
Deposits, Public Fund	114.0	113.6
Letters of Credit Outstanding, Amount	60.0
Deposits, Funds Held by Federally Recognized Tribes	31.1	31.3
Asset Pledged as Collateral [Member] | Funds Held by Federally Recognized Tribes [Member]
Debt Securities	32.4	40.7
Federal Home Loan Bank of Des Moines [Member]
Letters of Credit Outstanding, Amount	$ 60.0	$ 60.0

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- Definition

Represents funds held by federally recognized tribes as deposits.

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Amount of public fund deposit liabilities.

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