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		$ 12	(12)
Common stock issued for employee stock-based awards (in shares)		1,184,000
Shares surrendered by employees to pay taxes related to stock-based awards	(56,022)	$ (5)	(56,017)
Shares surrendered by employees to pay taxes related to stock-based awards (in shares)		(424,000)
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	74,431		74,431
Net Income (Loss)	138,539			138,539
Gain/Loss on net investment hedges, net of tax	(13,484)				(13,484)
Foreign currency translation adjustment	68,776				68,776
Change in defined benefit pension items, net of tax	(332)				(332)
Ending balance at Mar. 31, 2023	2,518,534	$ 1,182	1,749,574	866,276	(98,498)
Ending balance (in shares) at Mar. 31, 2023		118,334,000
Beginning balance at Dec. 31, 2022	2,400,549	$ 1,182	1,701,817	802,772	(105,222)
Beginning balance (in shares) at Dec. 31, 2022		118,161,000
Common stock issued for employee stock-based awards		$ 1	(1)
Common stock issued for employee stock-based awards (in shares)		94,000
Shares surrendered by employees to pay taxes related to stock-based awards	(3,147)	$ (1)	(3,146)
Shares surrendered by employees to pay taxes related to stock-based awards (in shares)		(23,000)
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	40,312		40,312
Net Income (Loss)	63,504			63,504
Gain/Loss on net investment hedges, net of tax	(1,999)				(1,999)
Foreign currency translation adjustment	8,747				8,747
Change in defined benefit pension items, net of tax	(24)				(24)
Ending balance at Mar. 31, 2023	2,518,534	$ 1,182	1,749,574	866,276	(98,498)
Ending balance (in shares) at Mar. 31, 2023		118,334,000
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		$ 13	(13)
Common stock issued for employee stock-based awards (in shares)		1,216,000
Shares surrendered by employees to pay taxes related to stock-based awards	$ (71,874)	$ (5)	(71,869)
Shares surrendered by employees to pay taxes related to stock-based awards (in shares)		(447,000)
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	139,378		139,378
Net Income (Loss)	180,832			180,832
Gain/Loss on net investment hedges, net of tax	(5,079)				(5,079)
Foreign currency translation adjustment	9,882				9,882
Change in defined benefit pension items, net of tax	(6)				(6)
Ending balance at Mar. 31, 2024	$ 2,943,132	$ 1,197	1,901,109	1,154,109	(113,283)
Ending balance (in shares) at Mar. 31, 2024	119,717,000	119,717,000
Beginning balance at Dec. 31, 2023	$ 2,806,653	$ 1,194	1,860,934	1,039,664	(95,139)
Beginning balance (in shares) at Dec. 31, 2023		119,445,000
Common stock issued for employee stock-based awards		$ 3	(3)
Common stock issued for employee stock-based awards (in shares)		266,000
Shares surrendered by employees to pay taxes related to stock-based awards	(17,538)	$ (1)	(17,537)
Shares surrendered by employees to pay taxes related to stock-based awards (in shares)		(96,000)
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	45,007		45,007
Net Income (Loss)	114,445			114,445
Gain/Loss on net investment hedges, net of tax	6,432				6,432
Foreign currency translation adjustment	(24,792)				(24,792)
Change in defined benefit pension items, net of tax	216				216
Ending balance at Mar. 31, 2024	$ 2,943,132	$ 1,197	$ 1,901,109	$ 1,154,109	$ (113,283)
Ending balance (in shares) at Mar. 31, 2024	119,717,000	119,717,000