Stock-Based Compensation - Stock-Based Compensation Expense (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Mar. 31, 2022	Mar. 31, 2021
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation	$ 8,657	$ 7,481	$ 16,548	$ 14,191
Restricted Stock Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation	8,058	7,048	15,255	13,192
Restricted Stock Units (RSUs) | Continuing Operations [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation	5,200	3,200	7,700	7,700
Employee Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation	599	433	1,293	999
Employee Stock | Continuing Operations [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation	$ 400	$ 200	$ 800	$ 500