Note 6 - Pledged Assets - Schedule of Financial Instruments Owned and Pledged as Collateral (Details) - USD ($) $ in Thousands	Dec. 31, 2025	Dec. 31, 2024
Accrued interest receivable	$ 49,127	$ 23,044
Restricted cash	58,696	25,723
Asset Pledged as Collateral [Member]
Accrued interest receivable	48,573	22,852
Restricted cash	58,696	25,723
Total	10,745,145	5,358,194
Asset Pledged as Collateral [Member] | Residential Mortgage-Backed Securities [Member] | Pass Through Certificate [Member]
Investment at fair value	10,489,655	5,193,570
Asset Pledged as Collateral [Member] | Residential Mortgage-Backed Securities [Member] | Structured Finance [Member]
Investment at fair value	13,088	15,498
Asset Pledged as Collateral [Member] | US Treasury Securities [Member]
Investment at fair value	135,133	100,551
Asset Pledged as Collateral [Member] | Repurchase Agreements [Member]
Accrued interest receivable	48,537	22,852
Restricted cash	51,171	22,818
Total	10,602,451	5,254,738
Asset Pledged as Collateral [Member] | Repurchase Agreements [Member] | Residential Mortgage-Backed Securities [Member] | Pass Through Certificate [Member]
Investment at fair value	10,489,655	5,193,570
Asset Pledged as Collateral [Member] | Repurchase Agreements [Member] | Residential Mortgage-Backed Securities [Member] | Structured Finance [Member]
Investment at fair value	13,088	15,498
Asset Pledged as Collateral [Member] | Repurchase Agreements [Member] | US Treasury Securities [Member]
Investment at fair value	0	0
Asset Pledged as Collateral [Member] | Derivative [Member]
Accrued interest receivable	36	0
Restricted cash	7,525	2,905
Total	142,694	103,456
Asset Pledged as Collateral [Member] | Derivative [Member] | Residential Mortgage-Backed Securities [Member] | Pass Through Certificate [Member]
Investment at fair value	0	0
Asset Pledged as Collateral [Member] | Derivative [Member] | Residential Mortgage-Backed Securities [Member] | Structured Finance [Member]
Investment at fair value	0	0
Asset Pledged as Collateral [Member] | Derivative [Member] | US Treasury Securities [Member]
Investment at fair value	$ 135,133	$ 100,551