Consolidated Statements of Stockholder's Equity - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Retained Earnings	Accumulated Other Comprehensive Loss
Beginning balance at Sep. 30, 2021	$ 2,038,468	$ 1,172	$ 1,718,504	$ 414,656	$ (95,864)
Beginning balance (in shares) at Sep. 30, 2021		117,163,000
Common stock issued for employee stock-based awards	0	$ 18	(18)
Common stock issued for employee stock-based awards (in shares)		1,737,000
Shares surrendered by employees to pay taxes related to stock-based awards	(68,991)	$ (6)	(68,985)
Shares surrendered by employees to pay taxes related to stock-based awards (in shares)		(597,000)
Common stock issued for employee stock purchase plan	21,207	$ 2	21,205
Common stock issued for employee stock purchase plan (in shares)		215,000
Compensation expense from stock-based awards	174,863		174,863
Net Income (Loss)	313,081			313,081
Repurchases of common stock	$ (125,000)	$ (11)	(124,989)
Repurchases of common stock (in shares)	(1,050,000.00)	(1,046,000)
Gain/Loss on net investment hedges, net of tax	$ 17,556				17,556
Foreign currency translation adjustment	(92,768)				(92,768)
Change in defined benefit pension items, net of tax	17,618				17,618
Ending balance at Sep. 30, 2022	2,296,034	$ 1,175	1,720,580	727,737	(153,458)
Ending balance (in shares) at Sep. 30, 2022		117,472,000
Common stock issued for employee stock-based awards	0	$ 18	(18)
Common stock issued for employee stock-based awards (in shares)		1,798,000
Shares surrendered by employees to pay taxes related to stock-based awards	(82,768)	$ (7)	(82,761)
Shares surrendered by employees to pay taxes related to stock-based awards (in shares)		(620,000)
Common stock issued for employee stock purchase plan	21,652	$ 2	21,650
Common stock issued for employee stock purchase plan (in shares)		196,000
Compensation expense from stock-based awards	161,454		161,454
Net Income (Loss)	$ 245,540			245,540
Repurchases of common stock (in shares)	0
Gain/Loss on net investment hedges, net of tax	$ (7,516)				(7,516)
Foreign currency translation adjustment	45,692				45,692
Change in defined benefit pension items, net of tax	(2,798)				(2,798)
Ending balance at Sep. 30, 2023	$ 2,677,290	$ 1,188	1,820,905	973,277	(118,080)
Ending balance (in shares) at Sep. 30, 2023	118,846,000	118,846,000
Common stock issued for employee stock-based awards	$ 0	$ 18	(18)
Common stock issued for employee stock-based awards (in shares)		1,733,000
Shares surrendered by employees to pay taxes related to stock-based awards	(101,924)	$ (6)	(101,918)
Shares surrendered by employees to pay taxes related to stock-based awards (in shares)		(612,000)
Common stock issued for employee stock purchase plan	25,674	$ 2	25,672
Common stock issued for employee stock purchase plan (in shares)		188,000
Compensation expense from stock-based awards	220,666		220,666
Net Income (Loss)	$ 376,333			376,333
Repurchases of common stock (in shares)	0
Gain/Loss on net investment hedges, net of tax	$ (16,315)				(16,315)
Foreign currency translation adjustment	36,465				36,465
Change in defined benefit pension items, net of tax	(3,791)				(3,791)
Ending balance at Sep. 30, 2024	$ 3,214,398	$ 1,202	$ 1,965,307	$ 1,349,610	$ (101,721)
Ending balance (in shares) at Sep. 30, 2024	120,155,000	120,155,000