| Employee Benefit Plans - Summary of Amounts Recognized in Accumulated Other Comprehensive Loss, Net of Income Tax (Detail) - USD ($) $ in Thousands | Mar. 31, 2021 | Mar. 31, 2020 | 
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| Pension Plans, Defined Benefit [Member] | ||
| Defined Benefit Plan Disclosure [Line Items] | ||
| Net actuarial loss | $ 6,990 | $ 9,285 | 
| Other Postretirement Benefit Plans [Member] | ||
| Defined Benefit Plan Disclosure [Line Items] | ||
| Net actuarial loss | $ 164 | $ 187 | 
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- Definition Amount, after tax, of accumulated other comprehensive income (loss) for gain (loss) of defined benefit plan, that has not been recognized in net periodic benefit (cost) credit. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef 
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- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. No definition available. 
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