v3.26.1
Note 13 - Treasury Stock and Repurchase Program - Treasury Stock at Cost (Details) - USD ($)
 12 Months Ended
Nov. 17, 2025
Apr. 30, 2026
Apr. 30, 2025
Apr. 30, 2024
Apr. 30, 2023
Apr. 30, 2022
Apr. 30, 2021
Balance, shares (in shares)   613,807 588,997 577,517 565,460 490,157 436,830
Balance, cost assigned   $ 16,575,000 $ 15,647,000 $ 15,194,000 $ 14,671,000 $ 9,967,000 $ 7,483,000
Balance, average cost per share (in dollars per share)   $ 27 $ 26.57 $ 26.31 $ 25.95 $ 20.33 $ 17.13
Balance, aggregate purchase price remaining under the program   $ 1,291,000 $ 758,000 $ 1,211,000 $ 1,266,000 $ 1,241,000 $ 474,000
Purchases effected in open market, shares (in shares) 14,015 24,810 [1] 11,480 [2] 12,057 [2] 75,303 [2] 53,327 [3]  
Purchases effected in open market, cost assigned $ 519,121 $ 928,000 [1] $ 453,000 [2] $ 523,000 [2] $ 4,704,000 [2] $ 2,484,000 [3]  
Purchases effected in open market, average cost per share (in dollars per share) $ 37.04 $ 37.4 [1] $ 39.46 [2] $ 43.38 [2] $ 62.47 [2] $ 46.58 [3]  
[1] (3)  Were acquired during the $3 million repurchase program authorized in October 2022 and the $2 million repurchase program authorized in October 2025. 
[2] (2)  Were acquired during the $3 million repurchase program authorized in May 2022 and the $3 million repurchase program authorized in October 2022. 
[3] (1)  Were acquired during the $2 million repurchase program authorized in July 2021 and the $2 million repurchase program authorized in March 2022. .