Restructuring and Other Costs, Net - Schedule of Restructuring and Other Costs, Net (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Restructuring Cost And Reserve [Line Items]
Restructuring and other costs, net	$ 1,760	$ 3,301	$ 2,777	$ 13,725
Personnel
Restructuring Cost And Reserve [Line Items]
Restructuring and other costs, net		2,452	381	3,133
Facilities
Restructuring Cost And Reserve [Line Items]
Restructuring and other costs, net	447		1,012
Restructuring Subtotal
Restructuring Cost And Reserve [Line Items]
Restructuring and other costs, net	447	2,452	1,393	3,133
Other
Restructuring Cost And Reserve [Line Items]
Restructuring and other costs, net	$ 1,313	$ 849	$ 1,384	$ 10,592