Note 15 - Commitments and Contingencies (Details Textual) $ in Thousands	12 Months Ended
	Dec. 31, 2024 USD ($)	Dec. 31, 2023 USD ($)
Off-Balance-Sheet, Credit Loss, Liability	$ 7,500	$ 7,400
Off-Balance-Sheet, Credit Loss, Liability, Credit Loss Expense (Reversal)	(81,000)	2,200
Federal Home Loan Bank of Des Moines [Member]
Letters of Credit Outstanding, Amount	$ 12,000	0
Federal Home Loan Bank (FHLB) [Member]
Letters of Credit, Number Outstanding	5
Bank of North Dakota [Member]
Letters of Credit, Number Outstanding	1
Letters of Credit Outstanding, Amount	$ 50,000	182,000
Bank of North Dakota [Member] | Letter of Credit [Member]
Debt Instrument, Collateral Amount	524,900	454,600
Unfunded Loan Commitment [Member]
Off-Balance-Sheet, Credit Loss, Liability	7,500	7,400
Off-Balance-Sheet, Credit Loss, Liability, Credit Loss Expense (Reversal)	$ 100	$ 2,200