Statements of Shareholders' Equity (Unaudited) (Parentheticals) - $ / shares |
3 Months Ended | |||||
|---|---|---|---|---|---|---|
Dec. 31, 2021 |
Sep. 30, 2021 |
Jun. 30, 2021 |
Dec. 31, 2020 |
Sep. 30, 2020 |
Jun. 30, 2020 |
|
| Common stock per share (in dollars per share) | $ 1.00 | $ 1.00 | $ 1.00 | $ 1.00 | $ 1.00 | $ 1.00 |
| Common stock per share (in dollars per share) | $ 1.00 | $ 1.00 | $ 1.00 | $ 1.00 | $ 1.00 | $ 1.00 |