Pension Plans - Schedule of Provision for Pension Benefit Obligation Recognized in Other Comprehensive Income (Detail) - USD ($) $ in Thousands	12 Months Ended
Mar. 31, 2021	Mar. 31, 2020	Mar. 31, 2019
Defined Benefit Plan Net Periodic Benefit Cost [Abstract]
Net actuarial (gain) / loss	$ (564)	$ (1,841)	$ 1,027
Amortization of prior service credit	(58)	23	14
Amortization of net loss		(216)	(154)
Provision for pension benefit obligation	$ (622)	$ (2,034)	$ 887

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- Definition

Amount, after tax, of gain (loss) for (increase) decrease in value of benefit obligation for change in actuarial assumptions and increase (decrease) in value of plan assets from experience different from that assumed of defined benefit plan, that has not been recognized in net periodic benefit (cost) credit.

+ References

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- Definition

Amount, after tax, of reclassification adjustment from accumulated other comprehensive (income) loss for prior service cost (credit) of defined benefit plan.

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- Definition

Amount, after tax and reclassification adjustment, of (increase) decrease in accumulated other comprehensive income for defined benefit plan.

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Amount, after tax, of reclassification adjustment from accumulated other comprehensive income (loss) for gain (loss) of defined benefit plan.

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