Employee Benefit Plans (Details) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2020
Compensation Related Costs [Abstract]
Maximum employer match as percent of employee contribution	50.00%
Maximum match from employer as a percent of participants' salary	6.00%
Contributions, net of forfeitures	$ 4.3	$ 2.1	$ 1.5
Deferred compensation plan assets	9.1	11.4
Benefit plan balance	$ 8.1	$ 7.0