Consolidated Statements of Stockholder's Equity - USD ($) $ in Thousands	Total	Previously Reported	Net Investment Hedging	Common Stock	Additional Paid-in Capital	Retained Earnings (Accumulated Deficit)	Retained Earnings (Accumulated Deficit) Previously Reported	Accumulated Other Comprehensive Loss	Accumulated Other Comprehensive Loss Net Investment Hedging
Beginning balance at Sep. 30, 2019	$ 1,201,998			$ 1,149	$ 1,502,949	$ (191,390)		$ (110,710)
Beginning balance (Accounting Standards Update 2016-02) at Sep. 30, 2019		$ (1,572)					$ (1,572)
Beginning balance (in shares) at Sep. 30, 2019				114,899,000
Common stock issued for employee stock-based awards				$ 14	(14)
Common stock issued for employee stock-based awards (in shares)				1,392,000
Shares surrendered by employees to pay taxes related to stock-based awards	(33,740)			$ (4)	(33,736)
Shares surrendered by employees to pay taxes related to stock-based awards (in shares)				(455,000)
Common stock issued for employee stock purchase plan	18,382			$ 2	18,380
Common stock issued for employee stock purchase plan (in shares)				289,000
Compensation expense from stock-based awards	115,149				115,149
Net income	$ 130,695					130,695
Unrealized gain (loss) on net investment hedges, net of tax			$ (13,242)						$ (13,242)
Repurchases of common stock (in shares)	0
Foreign currency translation adjustment	$ 22,076							22,076
Unrealized gain (loss) on available-for-sale securities, net of tax	188							188
Change in pension benefits, net of tax	(1,686)							(1,686)
Ending balance at Sep. 30, 2020	1,438,248			$ 1,161	1,602,728	(62,267)		(103,374)
Ending balance (in shares) at Sep. 30, 2020				116,125,000
Common stock issued for employee stock-based awards				$ 15	(15)
Common stock issued for employee stock-based awards (in shares)				1,490,000
Shares surrendered by employees to pay taxes related to stock-based awards	(53,077)			$ (4)	(53,073)
Shares surrendered by employees to pay taxes related to stock-based awards (in shares)				(466,000)
Common stock issued for employee stock purchase plan	21,575			$ 2	21,573
Common stock issued for employee stock purchase plan (in shares)				240,000
Compensation expense from stock-based awards	177,289				177,289
Net income	476,923					476,923
Unrealized gain (loss) on net investment hedges, net of tax	1,248								1,248
Repurchases of common stock	$ (30,000)			$ (2)	(29,998)
Repurchases of common stock (in shares)	(230,000)			(226,000)
Foreign currency translation adjustment	$ 1,613							1,613
Unrealized gain (loss) on available-for-sale securities, net of tax	(307)							(307)
Change in pension benefits, net of tax	4,956							4,956
Ending balance at Sep. 30, 2021	$ 2,038,468			$ 1,172	1,718,504	414,656		(95,864)
Ending balance (in shares) at Sep. 30, 2021	117,163,000			117,163,000
Common stock issued for employee stock-based awards				$ 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	313,081					313,081
Unrealized gain (loss) on net investment hedges, net of tax	17,556								$ 17,556
Repurchases of common stock	$ (125,000)			$ (11)	(124,989)
Repurchases of common stock (in shares)	(1,050,000.00)			(1,046,000)
Foreign currency translation adjustment	$ (92,768)							(92,768)
Unrealized gain (loss) on available-for-sale securities, net of tax	0
Change in pension benefits, 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			117,472