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		$ 11	(11)
Common stock issued for employee stock-based awards (in shares)		1,120,000
Shares surrendered by employees to pay taxes related to stock-based awards	(49,165)	$ (4)	(49,161)
Shares surrendered by employees to pay taxes related to stock-based awards (in shares)		(410,000)
Compensation expense from stock-based awards	45,942		45,942
Repurchases of common stock	$ (124,999)	$ (10)	(124,989)
Repurchases of common stock (in shares)	(1,003,000)	(1,003,000)
Net income	$ 46,089			46,089
Unrealized gain (loss) on net investment hedges, net of tax	2,495				2,495
Foreign currency translation adjustment	(5,668)				(5,668)
Change in pension benefits, net of tax	650				650
Ending balance at Dec. 31, 2021	1,953,812	$ 1,169	1,590,285	460,745	(98,387)
Ending balance (in shares) at Dec. 31, 2021		116,870,000
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		$ 11	(11)
Common stock issued for employee stock-based awards (in shares)		1,090,000
Shares surrendered by employees to pay taxes related to stock-based awards	$ (52,875)	$ (4)	(52,871)
Shares surrendered by employees to pay taxes related to stock-based awards (in shares)		(401,000)
Compensation expense from stock-based awards	$ 34,119		34,119
Repurchases of common stock (in shares)	0
Net income	$ 75,035			75,035
Unrealized gain (loss) on net investment hedges, net of tax	(11,485)				(11,485)
Foreign currency translation adjustment	60,029				60,029
Change in pension benefits, net of tax	(308)				(308)
Ending balance at Dec. 31, 2022	$ 2,400,549	$ 1,182	$ 1,701,817	$ 802,772	$ (105,222)
Ending balance (in shares) at Dec. 31, 2022	118,161,000	118,161,000