Note 7 - Offsetting Assets and Liabilities - Offsetting Liabilities (Details) - Liability [Member] - USD ($) $ in Thousands	Mar. 31, 2025	Dec. 31, 2024
Gross amount, recognized	$ 6,418,641	$ 5,025,875
Gross Amount, offset	0	0
Net Amount	6,418,641	5,025,875
Gross Amount, not recognized	(6,415,829)	(5,002,725)
Gross amount, not offset	(2,812)	(23,098)
Net amount, after deduction	0	52
Repurchase Agreements [Member]
Gross amount, recognized	6,418,641	5,025,543
Gross Amount, offset	0	0
Net Amount	6,418,641	5,025,543
Gross Amount, not recognized	(6,415,829)	(5,002,725)
Gross amount, not offset	(2,812)	(22,818)
Net amount, after deduction	$ 0	0
TBA Contracts [Member]
Gross amount, recognized		332
Gross Amount, offset		0
Net Amount		332
Gross Amount, not recognized		0
Gross amount, not offset		(280)
Net amount, after deduction		$ 52