v3.26.1
Note 15 - Employee Benefit Plans - Schedule of Components of Net Periodic Pension and Postretirement Benefit Cost (Details) - USD ($)
 3 Months Ended 9 Months Ended
Jun. 30, 2026
Jun. 30, 2025
Jun. 30, 2026
Jun. 30, 2025
Pension Plan [Member]        
Service cost $ 92,967 $ 96,858 $ 278,901 $ 290,574
Interest cost 380,324 352,602 1,140,972 1,057,806
Expected return on plan assets (427,888) (375,976) (1,283,664) (1,127,928)
Recognized loss 10,943 14,857 32,829 44,571
Net periodic pension cost 56,346 88,341 169,038 265,023
Postemployment Retirement Benefits [Member]        
Service cost 0 1,095 0 3,285
Interest cost 130,327 126,856 390,981 380,568
Expected return on plan assets (216,083) (182,430) (648,249) (547,290)
Recognized loss (50,507) (58,153) (151,521) (174,459)
Net periodic pension cost $ (136,263) $ (112,632) $ (408,789) $ (337,896)