Note 5 - Derivative and Other Hedging Instruments - Schedule of Derivative Positions (Details) - Short [Member] - USD ($) $ in Thousands		Jun. 30, 2024	Dec. 31, 2023
Five Year Treasury Note Futures [Member]
Average contract notional amount	[1]	$ 421,500	$ 421,500
Weighted average entry rate	[1]	4.42%	4.36%
Average receive rate	[1]	4.52%	4.04%
Open Equity	[1],[2]	$ (2,025)	$ (9,936)
Ten Year Ultra Futures [Member]
Average contract notional amount	[1]		$ 320,000
Weighted average entry rate	[1]		4.38%
Average receive rate	[1]		4.39%
Open Equity	[1],[2]		$ (11,393)
Three Month SOFR Futures Ending in December 2024 [Member]
Average contract notional amount		$ 25,000	$ 25,000
Weighted average entry rate		4.27%	4.27%
Average receive rate		5.15%	4.10%
Open Equity	[2]	$ 220	$ (44)
Three Month SOFR Futures Ending in March 2025 [Member]
Average contract notional amount		$ 25,000	$ 25,000
Weighted average entry rate		3.90%	3.90%
Average receive rate		4.86%	3.73%
Open Equity	[2]	$ 239	$ (43)
Three Month SOFR Futures, Ending June 2024 [Member}
Average contract notional amount			$ 25,000
Weighted average entry rate			5.08%
Average receive rate			4.99%
Open Equity	[2]		$ (24)
Three Month SOFR Futures Ending in June 2025 [Member]
Average contract notional amount		$ 25,000	$ 25,000
Weighted average entry rate		3.58%	3.58%
Average receive rate		4.57%	3.42%
Open Equity	[2]	$ 245	$ (41)
Three Month SOFR Futures Ending September 2024 [Member]
Average contract notional amount			$ 25,000
Weighted average entry rate			4.67%
Average receive rate			4.52%
Open Equity	[2]		$ (39)
Three Month SOFR Futures Ending in September 2025 [Member]
Average contract notional amount		$ 25,000	$ 25,000
Weighted average entry rate		3.37%	3.37%
Average receive rate		4.32%	3.21%
Open Equity	[2]	$ 237	$ (39)
Three Month SOFR Futures Ending in December 2025 [Member]
Average contract notional amount		$ 25,000	$ 25,000
Weighted average entry rate		3.25%	3.25%
Average receive rate		4.12%	3.10%
Open Equity	[2]	$ 218	$ (37)
Three Month SOFR Futures Ending in March 2026 [Member]
Average contract notional amount		$ 25,000	$ 25,000
Weighted average entry rate		3.21%	3.21%
Average receive rate		3.97%	3.07%
Open Equity	[2]	$ 191	$ (35)

[1] 5-Year T-Note futures contracts were valued at a price of $106.58 at June 30, 2024 and $108.77 at December 31, 2023. The contract values of the short positions were $449.2 million and $458.5 million at June 30, 2024 and December 31, 2023, respectively. 10-Year T-Note futures contracts were valued at a price of $112.89 at December 31, 2023.The contract values of the short position was $361.2 million at June 30, 2024 and December 31, 2023, respectively.

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