Stockholders Equity - Treasury stock activity (Details) - shares	3 Months Ended	12 Months Ended
	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2020
Stockholder's Equity
Number of shares at beginning of year		195,638	58,909	53,469
Repurchases of common stock to satisfy employee payroll taxes	37,002	37,002	23,751	5,440
Repurchases of common stock from share repurchase plan		142,392	112,978
Number of shares at end of year	195,638	375,032	195,638	58,909