Note 5 - Derivative and Other Hedging Instruments - Schedule of Derivative Positions (Details) - Short [Member] - USD ($) $ in Thousands		Dec. 31, 2025		Dec. 31, 2024
Five Year Treasury Note Futures [Member]
Average contract notional amount	[1],[2]	$ 122,500		$ 312,500
Weighted average entry rate	[1]	3.65%		4.22%	[2]
Average receive rate	[1]	3.65%		4.37%	[2]
Open Equity	[1],[3]	$ 10		$ 1,890	[2]
Ten Year T-Note Futures [Member]
Average contract notional amount		$ 90,000	[1]	$ 93,500	[2]
Weighted average entry rate		3.79%	[1]	4.30%	[2]
Average receive rate		3.91%	[1]	4.49%	[2]
Open Equity	[3]	$ 739	[1]	$ 1,119	[2]
Ten Year Ultra Futures [Member]
Average contract notional amount		$ 60,000	[1]	$ 32,500	[2]
Weighted average entry rate		4.03%	[1]	4.25%	[2]
Average receive rate		4.14%	[1]	4.58%	[2]
Open Equity	[3]	$ 575	[1]	$ 914	[2]
Three Month SOFR Futures Ending in December 2025 [Member]
Average contract notional amount		$ 97,500
Weighted average entry rate		3.73%
Average receive rate		3.69%
Open Equity	[3]	$ (44)
Three Month SOFR Futures Ending in March 2026 [Member]
Average contract notional amount		$ 97,500
Weighted average entry rate		3.55%
Average receive rate		3.52%
Open Equity	[3]	$ (33)
Three Month SOFR Futures Ending in June 2026 [Member]
Average contract notional amount		$ 97,500
Weighted average entry rate		3.38%
Average receive rate		3.31%
Open Equity	[3]	$ (66)
Three Month SOFR Futures Ending in September 2026 [Member]
Average contract notional amount		$ 97,500
Weighted average entry rate		3.27%
Average receive rate		3.16%
Open Equity	[3]	$ (111)
Three Month SOFR Futures Ending in December 2026 [Member]
Average contract notional amount		$ 97,500
Weighted average entry rate		3.22%
Average receive rate		3.11%
Open Equity	[3]	$ (105)
Three Month SOFR Futures Ending in March 2027 [Member]
Average contract notional amount		$ 97,500
Weighted average entry rate		3.21%
Average receive rate		3.11%
Open Equity	[3]	$ (90)
Five Year 3.75% ERIS SOFR Swap Futures Ending in December 2025 Member]
Average contract notional amount	[4]	$ 10,000
Weighted average entry rate	[4]	3.48%
Average receive rate	[4]	3.45%
Open Equity	[3],[4]	$ (13)

[1] 5-Year T-Note futures contracts were valued at a price of $109.20 at September 30, 2025 and $106.30 at December 31, 2024. The contract values of the short positions were $614.3 million and $332.2 million at September 30, 2025 and December 31, 2024, respectively. 10-Year T-Note futures contracts were valued at a price of $112.50 at September 30, 2025 and $108.75 at December 31, 2024. The contract values of the short positions were $257.1 million and $101.7 million at September 30, 2025 and December 31, 2024, respectively. 10-Year Ultra futures contracts were valued at a price of $115.80 at September 30, 2025 and $111.31 at December 31, 2024. The contract values of the short positions were $228.7 million and $36.2 million at September 30, 2025 and December 31, 2024, respectively.

[2] 5-Year T-Note futures contracts were valued at a price of $109.30 as of December 31, 2025 and $106.30 as of December 31, 2024. The contract values of the short positions were $133.9 million and $332.2 million as of December 31, 2025 and 2024, respectively. 10-Year T-Note futures contracts were valued at a price of $112.44 as of December 31, 2025 and $108.75 as of December 31, 2024.. The contract values of the short positions were $101.2 million and $101.7 million as of December 31, 2025 and 2024, respectively. 10-Year Ultra futures contracts were valued at price of $115.02 as of December 31, 2025 and $111.31 as of December 31, 2024. The contract value of the short positions was $69.0 million and $36.2 million as of December 31, 2025 and 2024, respectively.

[3] Open equity represents the cumulative gains (losses) recorded on open futures positions from inception.

[4] ERIS swap futures are exchange traded futures that replicate the cash flows of an underlying swap position.