Consolidated Statements of Stockholder's Equity (Unaudited) - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-In Capital	Retained Earnings	Accumulated Other Comprehensive Loss
Beginning balance at Sep. 30, 2022	$ 2,296,034	$ 1,175	$ 1,720,580	$ 727,737	$ (153,458)
Beginning balance (in shares) at Sep. 30, 2022		117,472,000
Common stock issued for employee stock-based awards		$ 18	(18)
Common stock issued for employee stock-based awards (in shares)		1,766,000
Shares surrendered by employees to pay taxes related to stock-based awards	(81,194)	$ (7)	(81,187)
Shares surrendered by employees to pay taxes related to stock-based awards (in shares)		(609,000)
Common stock issued for employee stock purchase plan	10,592		10,592
Common stock issued for employee stock purchase plan (in shares)		102,000
Compensation expense from stock-based awards	117,475		117,475
Net Income (Loss)	199,937			199,937
Gain/Loss on net investment hedges, net of tax	(14,005)				(14,005)
Foreign currency translation adjustment	70,181				70,181
Change in defined benefit pension items, net of tax	(356)				(356)
Ending balance at Jun. 30, 2023	2,598,664	$ 1,186	1,767,442	927,674	(97,638)
Ending balance (in shares) at Jun. 30, 2023		118,731,000
Beginning balance at Mar. 31, 2023	2,518,534	$ 1,182	1,749,574	866,276	(98,498)
Beginning balance (in shares) at Mar. 31, 2023		118,334,000
Common stock issued for employee stock-based awards		$ 6	(6)
Common stock issued for employee stock-based awards (in shares)		582,000
Shares surrendered by employees to pay taxes related to stock-based awards	(25,172)	$ (2)	(25,170)
Shares surrendered by employees to pay taxes related to stock-based awards (in shares)		(185,000)
Compensation expense from stock-based awards	43,044		43,044
Net Income (Loss)	61,398			61,398
Gain/Loss on net investment hedges, net of tax	(521)				(521)
Foreign currency translation adjustment	1,405				1,405
Change in defined benefit pension items, net of tax	(24)				(24)
Ending balance at Jun. 30, 2023	2,598,664	$ 1,186	1,767,442	927,674	(97,638)
Ending balance (in shares) at Jun. 30, 2023		118,731,000
Beginning balance at Sep. 30, 2023	$ 2,677,290	$ 1,188	1,820,905	973,277	(118,080)
Beginning balance (in shares) at Sep. 30, 2023	118,846,000	118,846,000
Common stock issued for employee stock-based awards		$ 18	(18)
Common stock issued for employee stock-based awards (in shares)		1,702,000
Shares surrendered by employees to pay taxes related to stock-based awards	$ (99,945)	$ (7)	(99,938)
Shares surrendered by employees to pay taxes related to stock-based awards (in shares)		(601,000)
Common stock issued for employee stock purchase plan	12,709	$ 1	12,708
Common stock issued for employee stock purchase plan (in shares)		102,000
Compensation expense from stock-based awards	176,958		176,958
Net Income (Loss)	249,810			249,810
Gain/Loss on net investment hedges, net of tax	(2,787)				(2,787)
Foreign currency translation adjustment	538				538
Change in defined benefit pension items, net of tax	106				106
Ending balance at Jun. 30, 2024	$ 3,014,679	$ 1,200	1,910,615	1,223,087	(120,223)
Ending balance (in shares) at Jun. 30, 2024	120,049,000	120,049,000
Beginning balance at Mar. 31, 2024	$ 2,943,132	$ 1,197	1,901,109	1,154,109	(113,283)
Beginning balance (in shares) at Mar. 31, 2024		119,717,000
Common stock issued for employee stock-based awards		$ 5	(5)
Common stock issued for employee stock-based awards (in shares)		486,000
Shares surrendered by employees to pay taxes related to stock-based awards	(28,071)	$ (2)	(28,069)
Shares surrendered by employees to pay taxes related to stock-based awards (in shares)		(154,000)
Compensation expense from stock-based awards	37,580		37,580
Net Income (Loss)	68,978			68,978
Gain/Loss on net investment hedges, net of tax	2,292				2,292
Foreign currency translation adjustment	(9,344)				(9,344)
Change in defined benefit pension items, net of tax	112				112
Ending balance at Jun. 30, 2024	$ 3,014,679	$ 1,200	$ 1,910,615	$ 1,223,087	$ (120,223)
Ending balance (in shares) at Jun. 30, 2024	120,049,000	120,049,000