Note 7 - Offsetting Assets and Liabilities - Offsetting Liabilities (Details) - Liability [Member] - USD ($) $ in Thousands	Mar. 31, 2026	Dec. 31, 2025
Gross amount, recognized	$ 10,865,358	$ 10,117,312
Gross Amount, offset	0	0
Net Amount	10,865,358	10,117,312
Gross Amount, not recognized	(10,782,111)	(10,064,295)
Gross amount, not offset	(83,247)	(53,017)
Net amount, after deduction	0	0
Repurchase Agreements [Member]
Gross amount, recognized	10,864,723	10,115,466
Gross Amount, offset	0	0
Net Amount	10,864,723	10,115,466
Gross Amount, not recognized	(10,782,111)	(10,064,295)
Gross amount, not offset	(82,612)	(51,171)
Net amount, after deduction	0	0
TBA Contracts [Member]
Gross amount, recognized	635	1,846
Gross Amount, offset	0	0
Net Amount	635	1,846
Gross Amount, not recognized	0	0
Gross amount, not offset	(635)	(1,846)
Net amount, after deduction	$ 0	$ 0