Note 13 - Fair Value Measurement - Quantitative Information (Details) $ in Thousands	Sep. 30, 2024 USD ($)	Jun. 30, 2024 USD ($)	Dec. 31, 2023 USD ($)	Sep. 30, 2023 USD ($)	Jun. 30, 2023 USD ($)	Dec. 31, 2022 USD ($)
Servicing rights on sold loans, at fair value	$ 3,584		$ 3,793
Fair Value, Recurring [Member]
Servicing rights on sold loans, at fair value	3,584		3,793
Fair Value, Inputs, Level 3 [Member] | Fair Value, Recurring [Member]
Servicing rights on sold loans, at fair value	3,584	$ 3,740	3,793	$ 3,729	$ 3,825	$ 3,887
Fair Value, Inputs, Level 3 [Member] | Fair Value, Recurring [Member] | Mortgage-Backed Securities, Issued by Private Enterprises [Member]
Partnership investments	$ 17,095	$ 17,231	$ 27,469	$ 29,192	$ 29,378	$ 29,599
Fair Value, Inputs, Level 3 [Member] | Fair Value, Recurring [Member] | Measurement Input, Discount Rate [Member] | Weighted Average [Member]
Sold loan servicing rights, measurement input	10.92
Fair Value, Inputs, Level 3 [Member] | Fair Value, Recurring [Member] | Valuation Technique, Discounted Cash Flow [Member] | Measurement Input, Constant Prepayment Rate [Member] | Weighted Average [Member]
Sold loan servicing rights, measurement input	7.83		7.39
Fair Value, Inputs, Level 3 [Member] | Fair Value, Recurring [Member] | Valuation Technique, Discounted Cash Flow [Member] | Sold Loan Servicing Rights [Member]
Servicing rights on sold loans, at fair value	$ 3,584		$ 3,793
Fair Value, Inputs, Level 3 [Member] | Fair Value, Recurring [Member] | Valuation Technique, Consensus Pricing Model [Member] | Mortgage-Backed Securities, Issued by Private Enterprises [Member]
Assets, fair value	17,095		27,469
Partnership investments	$ 12,650		$ 13,183
Fair Value, Inputs, Level 3 [Member] | Fair Value, Recurring [Member] | Valuation Technique, Consensus Pricing Model [Member] | Measurement Input, Offered Price [Member] | Minimum [Member]
Measurement input	99		98
Fair Value, Inputs, Level 3 [Member] | Fair Value, Recurring [Member] | Valuation Technique, Consensus Pricing Model [Member] | Measurement Input, Offered Price [Member] | Maximum [Member]
Measurement input	100		100