Income Taxes - Provision for Income Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2022
Current:
Federal	$ 110,402	$ 112,456	$ 50,403
State	10,199	16,844	8,952
Foreign	35,943	42,327	30,597
Current income tax	156,544	171,627	89,952
Deferred:
Federal	(26,227)	(37,884)	8,165
State	(1,712)	(15,025)	507
Foreign	609	5,531	(856)
Deferred income taxes	(27,330)	(47,378)	7,816
Total provision	$ 129,214	$ 124,249	$ 97,768