Employee Benefit Plans - Defined Benefit Pension Plans (Details) - USD ($) $ in Millions |
12 Months Ended | ||
|---|---|---|---|
Jun. 30, 2019 |
Jun. 30, 2018 |
Jun. 30, 2017 |
|
| Defined Benefit Plan Disclosure [Line Items] | |||
| Benefit expense | $ 4.4 | $ 4.9 | $ 4.3 |
| Benefit obligation | 50.8 | 42.8 | 39.7 |
| SORP | Supplemental Employee Retirement Plan | |||
| Defined Benefit Plan Disclosure [Line Items] | |||
| Benefit expense | 3.9 | 4.3 | 3.6 |
| Benefit obligation | 45.5 | 38.3 | 35.4 |
| SERP | Supplemental Employee Retirement Plan | |||
| Defined Benefit Plan Disclosure [Line Items] | |||
| Benefit expense | 0.5 | 0.6 | 0.7 |
| Benefit obligation | $ 5.4 | $ 4.5 | $ 4.3 |