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