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Employee Benefit Plans - Additional Information (Detail) - USD ($) $ in Millions | 3 Months Ended | 9 Months Ended |
--- | --- | --- | ---
Mar. 31, 2020 | Mar. 31, 2019 | Dec. 31, 2020 | Dec. 31, 2019
Pension Plans, Defined Benefit |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Defined benefit plan, employer contributions | $ 0.0 | $ 0.0 |  |
Supplemental Executive Retirement Plan |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Defined benefit plan, employer contributions | 0.4 |  |  |
Obligations under the supplemental plan | $ 21.5 |  |  | $ 21.4
Supplemental Executive Retirement Plan | Scenario, Forecast |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Defined benefit plan, employer contributions |  |  | $ 1.2 |

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