Restructuring and Other Costs, Net - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Mar. 31, 2021	Mar. 31, 2020
Restructuring Cost And Reserve [Line Items]
Restructuring charges (reversal)	$ 537	$ 2,870	$ 1,017	$ 10,424
Facilities Closure
Restructuring Cost And Reserve [Line Items]
Restructuring charges (reversal)	447		565
Severance Charge
Restructuring Cost And Reserve [Line Items]
Restructuring charges (reversal)	$ 45	321	$ 381	681
Professional Services Fees
Restructuring Cost And Reserve [Line Items]
Restructuring charges (reversal)		$ 2,500		$ 9,700