XML 33 R58.htm IDEA: XBRL DOCUMENT v3.20.1
Note K - Stock-based Compensation Plans - Options Valuation Assumptions (Details)
12 Months Ended
Apr. 30, 2020
Apr. 30, 2019
Apr. 30, 2018
Expected terms (years) (Year) 5 years 182 days 5 years 182 days 5 years 182 days
Risk-free interest rate 1.75% 2.79% 1.81%
Volatility 39.00% 36.00% 36.00%
Dividend yield