Retirement and Deferred Compensation Plan - 401(k) Retirement Plan (Details) - USD ($) $ in Millions |
12 Months Ended | ||
---|---|---|---|
Sep. 30, 2023 |
Sep. 30, 2022 |
Sep. 30, 2021 |
|
Defined Contribution Plan Disclosure [Line Items] | |||
Employer matching contribution percentage | 50.00% | ||
Percentage of maximum contributions per employee | 6.00% | ||
Contribution vesting period | 5 years | ||
Employer contribution amount | $ 3.2 | $ 3.5 | $ 3.2 |
Total matching contributions forfeited by plan participants during period | $ 0.7 | $ 0.3 | $ 0.8 |
Minimum | |||
Defined Contribution Plan Disclosure [Line Items] | |||
Percentage of employee deferral or contribution | 1.00% | ||
Maximum | |||
Defined Contribution Plan Disclosure [Line Items] | |||
Percentage of employee deferral or contribution | 80.00% |