Note 7 - Offsetting Assets and Liabilities - Offsetting Liabilities (Details) - Liability [Member] - USD ($) $ in Thousands	Dec. 31, 2024	Dec. 31, 2023
Gross amount, recognized	$ 5,025,875	$ 3,718,343
Gross Amount, offset	0	0
Net Amount	5,025,875	3,718,343
Gross Amount, not recognized	(5,002,725)	(3,705,649)
Gross amount, not offset	(23,098)	(12,694)
Net amount, after deduction	52	0
Repurchase Agreements [Member]
Gross amount, recognized	5,025,543	3,705,649
Gross Amount, offset	0	0
Net Amount	5,025,543	3,705,649
Gross Amount, not recognized	(5,002,725)	(3,705,649)
Gross amount, not offset	(22,818)	0
Net amount, after deduction	0	0
TBA Contracts [Member]
Gross amount, recognized	332	12,694
Gross Amount, offset	0	0
Net Amount	332	12,694
Gross Amount, not recognized	0	0
Gross amount, not offset	(280)	(12,694)
Net amount, after deduction	$ 52	$ 0