Restructuring and Other Costs, Net - Schedule of Accrual Activity Relating to Restructuring Charges (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2022
Restructuring Cost And Reserve [Line Items]
Beginning Balance	$ 1,582	$ 5,154	$ 5,035
Restructuring and other costs, net	17,077	11,917	8,965
Non-cash adjustment	(834)	2,814	(4,708)
Cash payments	(13,522)	(18,305)	(4,082)
Foreign exchange impact on ending balance	27	2	(56)
Ending Balance	4,330	1,582	5,154
Personnel
Restructuring Cost And Reserve [Line Items]
Beginning Balance	549	1,277	1,620
Restructuring and other costs, net	13,410	7,778	1,676
Cash payments	(10,231)	(8,498)	(2,021)
Foreign exchange impact on ending balance	30	(8)	2
Ending Balance	3,758	549	1,277
Facilities
Restructuring Cost And Reserve [Line Items]
Beginning Balance	1,033	1,600	1,881
Restructuring and other costs, net	73	460	673
Non-cash adjustment	(534)	(486)	(708)
Cash payments	(569)	(551)	(188)
Foreign exchange impact on ending balance	(3)	10	(58)
Ending Balance		1,033	1,600
Restructuring Subtotal
Restructuring Cost And Reserve [Line Items]
Beginning Balance	1,582	2,877	3,501
Restructuring and other costs, net	13,483	8,238	2,349
Non-cash adjustment	(534)	(486)	(708)
Cash payments	(10,800)	(9,049)	(2,209)
Foreign exchange impact on ending balance	27	2	(56)
Ending Balance	3,758	1,582	2,877
Other
Restructuring Cost And Reserve [Line Items]
Beginning Balance		2,277	1,534
Restructuring and other costs, net	3,594	3,679	6,616
Non-cash adjustment	(300)	3,300	(4,000)
Cash payments	(2,722)	$ (9,256)	(1,873)
Ending Balance	$ 572		$ 2,277