Note 17 - Share-based Compensation - Stock Options, Valuation Assumptions (Details) - $ / shares |
12 Months Ended | ||
|---|---|---|---|
Jun. 30, 2020 |
Jun. 30, 2019 |
Jun. 30, 2018 |
|
| Grant date fair value (in dollars per share) | $ 17.27 | ||
| Employees [Member] | |||
| Volatility | 30.80% | ||
| Risk-free rate of return | 1.62% | ||
| Dividend yield | 4.42% | ||
| Expected average life (years) (Year) | 5 years 328 days | ||
| Grant date fair value (in dollars per share) | $ 2.85 | ||
| Independent Directors [Member] | |||
| Volatility | 30.80% | 31.30% | 31.50% |
| Risk-free rate of return | 1.55% | 2.80% | 1.76% |
| Dividend yield | 3.97% | 3.24% | 2.47% |
| Expected average life (years) (Year) | 5 years 109 days | 5 years | 4 years 219 days |
| Grant date fair value (in dollars per share) | $ 3.30 | $ 5.30 | $ 6.93 |
| Fair value as a % of exercise price | 18.80% | 22.60% | 22.50% |