Note 6 - Pledged Assets - Schedule of Financial Instruments Pledged as Collateral From Counterparties (Details) - USD ($) $ in Thousands	Mar. 31, 2026	Dec. 31, 2025
Assets pledged	$ 360,282	$ 141,633
Cash [Member]
Assets pledged	531	12,909
US Treasury Securities [Member]
Assets pledged	359,751	128,724
Repurchase Agreements [Member]
Assets pledged	743	12,549
Repurchase Agreements [Member] | Cash [Member]
Assets pledged	194	12,549
Repurchase Agreements [Member] | US Treasury Securities [Member]
Assets pledged	549	0
Reverse Repurchase Agreement [Member]
Assets pledged	359,202	128,724
Reverse Repurchase Agreement [Member] | Cash [Member]
Assets pledged	0	0
Reverse Repurchase Agreement [Member] | US Treasury Securities [Member]
Assets pledged	359,202	128,724
Derivative [Member]
Assets pledged	337	360
Derivative [Member] | Cash [Member]
Assets pledged	337	360
Derivative [Member] | US Treasury Securities [Member]
Assets pledged	$ 0	$ 0