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Employee Benefit Plans - Additional Information (Detail) - USD ($) | 3 Months Ended |
--- | --- | ---
Mar. 31, 2019 | Mar. 31, 2018 | Dec. 31, 2018
Pension Plans, Defined Benefit |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Defined benefit plan, employer contributions | $ 0 | $ 0 |
Supplemental Executive Retirement Plan |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Obligations under the supplemental plan | $ 20,500,000 |  | $ 21,400,000

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- Details
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