Stock-Based Compensation - Schedule of Stock Options Activity (Details) - $ / shares	12 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2019
Shares
Outstanding at beginning of period (in shares)	392,465	523,754	533,052
Granted (in shares)	0	950	30,782
Exercised (in shares)	(278,206)	(128,921)	(31,450)
Forfeited (in shares)	0	(3,318)	(8,630)
Outstanding at end of period (in shares)	114,259	392,465	523,754
Exercisable at end of period (in shares)	113,309	354,796	470,501
Weighted- Average Exercise Price
Outstanding at beginning or period (in dollars per share)	$ 15.47	$ 14.34	$ 14.26
Granted (in dollars per share)	0	10.67	10.23
Exercised (in dollars per share)	14.48	11.01	10.00
Forfeited (in dollars per share)	0	9.55	10.45
Outstanding at end of period (in dollars per share)	17.89	15.47	14.34
Exercisable at end of period (in dollars per share)	$ 17.95	$ 15.90	$ 14.42