Fair Value Measurement - Summary of Assets and Liabilities Carried at Fair Value (Detail) - Fair Value, Measurements, Recurring - USD ($) $ in Thousands	Sep. 30, 2021	Mar. 31, 2021
ASSETS
Total assets at fair value on a recurring basis	$ 1,715	$ 1,194
Liabilities [Abstract]
Total liabilities at fair value on a recurring basis	107	32
Level 2
ASSETS
Total assets at fair value on a recurring basis	1,715	1,194
Liabilities [Abstract]
Total liabilities at fair value on a recurring basis	107	32
Diesel Fuel Contracts
ASSETS
Derivative assets – diesel fuel contracts	1,715	1,194
Liabilities [Abstract]
Derivative liabilities – diesel fuel contracts	107	32
Diesel Fuel Contracts \| Level 2
ASSETS
Derivative assets – diesel fuel contracts	1,715	1,194
Liabilities [Abstract]
Derivative liabilities – diesel fuel contracts	$ 107	$ 32

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Fair value portion of probable future economic benefits obtained or controlled by an entity as a result of past transactions or events.

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Fair value, before effects of master netting arrangements, of a financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes assets elected not to be offset. Excludes assets not subject to a master netting arrangement.

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Fair value, before effects of master netting arrangements, of a financial liability or contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes liabilities elected not to be offset. Excludes liabilities not subject to a master netting arrangement.

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Fair value measurement recurring basis asset (liability) and mezzanine equity value.

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