Consolidated Statements of Stockholder's Equity - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-In Capital	Retained Earnings (Accumulated Deficit)	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		$ 12	(12)
Common stock issued for employee stock-based awards (in shares)		1,171,000
Shares surrendered by employees to pay taxes related to stock-based awards	(50,595)	$ (4)	(50,591)
Shares surrendered by employees to pay taxes related to stock-based awards (in shares)		(422,000)
Common stock issued for employee stock purchase plan	10,857	$ 1	10,856
Common stock issued for employee stock purchase plan (in shares)		110,000
Compensation expense from stock-based awards	83,863		83,863
Repurchases of common stock	$ (125,000)	$ (11)	(124,989)
Repurchases of common stock (in shares)	(1,046,000)	(1,046,000)
Net income	$ 135,768			135,768
Unrealized gain (loss) on net investment hedges, net of tax	6,192				6,192
Foreign currency translation adjustment	(17,024)				(17,024)
Change in pension benefits, net of tax	1,448				1,448
Ending balance at Mar. 31, 2022	2,083,977	$ 1,170	1,637,631	550,424	(105,248)
Ending balance (in shares) at Mar. 31, 2022		116,976,000
Beginning balance at Dec. 31, 2021	1,953,812	$ 1,169	1,590,285	460,745	(98,387)
Beginning balance (in shares) at Dec. 31, 2021		116,870,000
Common stock issued for employee stock-based awards		$ 1	(1)
Common stock issued for employee stock-based awards (in shares)		51,000
Shares surrendered by employees to pay taxes related to stock-based awards	(1,430)		(1,430)
Shares surrendered by employees to pay taxes related to stock-based awards (in shares)		(12,000)
Common stock issued for employee stock purchase plan	10,857	$ 1	10,856
Common stock issued for employee stock purchase plan (in shares)		110,000
Compensation expense from stock-based awards	37,921		37,921
Repurchases of common stock	$ (1)	$ (1)
Repurchases of common stock (in shares)	(43,000)	(43,000)
Net income	$ 89,679			89,679
Unrealized gain (loss) on net investment hedges, net of tax	3,697				3,697
Foreign currency translation adjustment	(11,356)				(11,356)
Change in pension benefits, net of tax	798				798
Ending balance at Mar. 31, 2022	2,083,977	$ 1,170	1,637,631	550,424	(105,248)
Ending balance (in shares) at Mar. 31, 2022		116,976,000
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	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
Repurchases of common stock (in shares)	0
Net income	$ 138,539			138,539
Unrealized gain (loss) on net investment hedges, net of tax	(13,484)				(13,484)
Foreign currency translation adjustment	68,776				68,776
Change in pension benefits, 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	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
Repurchases of common stock (in shares)	0
Net income	$ 63,504			63,504
Unrealized gain (loss) on net investment hedges, net of tax	(1,999)				(1,999)
Foreign currency translation adjustment	8,747				8,747
Change in pension benefits, 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	118,334,000