Balance Sheets (Parenthetical) - USD ($)	Sep. 30, 2021	Sep. 30, 2020
Statement Of Financial Position [Abstract]
Allowance for uncollectable accounts	$ 0	$ 0
Common stock, par value	$ 0.01666	$ 0.01666
Common stock, shares authorized	36,000,500	24,000,500
Common stock, shares issued	32,770,433	22,647,306
Common stock, shares outstanding	32,770,433	22,647,306
Treasury stock, shares	388,545	411,487