Income Taxes - Summary of Federal Income Tax Rate and Effective Income Tax Rate (Details) - USD ($) $ in Thousands		12 Months Ended
	Jun. 01, 2022	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2023
Reconciliation, Amount
Statutory federal income tax rate		$ 193,237	$ 98,482	$ 69,839
State income taxes, net of federal tax benefit		6,124	4,631	577
Federal research and development credits		(8,552)	(11,203)	(7,751)
Uncertain tax positions		(1,904)	7,268	23,302
Foreign tax credit		(14,410)	(30,119)	(11,415)
Foreign rate differences		(12,135)	(15,368)	(20,829)
Foreign tax on U.S. provision		14,452	15,120	11,415
Excess tax benefits from restricted stock		(8,534)	(9,225)	(6,963)
U.S. permanent items		(920)	2,711	5,341
Non-deductible compensation		9,096	10,157	8,344
Base Erosion Anti-Abuse Tax (BEAT)		2,653	3,264	0
GILTI, net of foreign tax credits		27,008	31,388	17,861
Foreign-Derived Intangible Income (FDII)		(20,162)	(15,148)	(8,987)
Non-deductible imputed interest		0	0	6,292
Other, net		227	671	0
Provision for income taxes		$ 186,180	$ 92,629	$ 87,026
Reconciliation, Percent
Statutory federal income tax rate		21.00%	21.00%	21.00%
State income taxes, net of federal tax benefit		1.00%	1.00%	0.00%
Federal research and development credits		(1.00%)	(2.00%)	(2.00%)
Uncertain tax positions		0.00%	2.00%	7.00%
Foreign tax credit		(2.00%)	(7.00%)	(3.00%)
Foreign rate differences		(1.00%)	(3.00%)	(6.00%)
Foreign tax on U.S. provision		2.00%	3.00%	3.00%
Excess tax benefits from restricted stock		(1.00%)	(2.00%)	(2.00%)
U.S. permanent items		0.00%	0.00%	2.00%
Non-deductible compensation		1.00%	2.00%	3.00%
Base Erosion Anti-Abuse Tax (BEAT)		0.00%	1.00%	0.00%
GILTI, net of foreign tax credits		3.00%	7.00%	5.00%
Foreign-Derived Intangible Income (FDII)		(2.00%)	(3.00%)	(3.00%)
Non-deductible imputed interest		0.00%	0.00%	2.00%
Other, net		(1.00%)	0.00%	(1.00%)
Provision for income taxes		20.00%	20.00%	26.00%
PLM Services Business Disposition
Reconciliation, Amount
Sale of a portion of the PLM services business	$ 60,400