v3.26.1
Note 3 - Mortgage-backed Securities - Treasury Note Portfolio (Details) (Parentheticals)
Jun. 30, 2026
U.S. Treasury Note, 1.375%, Maturing August 31, 2026 [Member]  
Investment Interest Rate 1.375%
U.S. Treasury Note, 0.75%, Maturing August 31, 2026 [Member]  
Investment Interest Rate 0.75%