Fair Value Measurement - Summary of Assets and Liabilities Carried at Fair Value (Detail) - Fair Value, Measurements, Recurring [Member] - USD ($) $ in Thousands	Jun. 30, 2020	Mar. 31, 2020
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets at fair value on a recurring basis	$ 106	$ 36
Total liabilities at fair value on a recurring basis	1,216	2,228
Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets at fair value on a recurring basis	106	36
Total liabilities at fair value on a recurring basis	1,216	2,228
Diesel Fuel Contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	106	36
Derivative liabilities	1,216	2,228
Diesel Fuel Contracts [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	106	36
Derivative liabilities	$ 1,216	$ 2,228