Share-Based Compensation Plans - Schedule of Total Gross Share-based Compensation Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2019
Stock Options
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Gross share-based compensation expense	$ 4,722	$ 4,406	$ 4,267
Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Gross share-based compensation expense	8,754	8,259	11,400
Performance share units
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Gross share-based compensation expense	3,662	1,957	1,279
ESPP
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Gross share-based compensation expense	$ 2,540	$ 1,774	$ 1,281