| Income Taxes - Components of Income (Loss) Before Provision for Income Taxes (Detail) - USD ($) $ in Thousands | 12 Months Ended | ||
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| Mar. 31, 2021 | Mar. 31, 2020 | Mar. 31, 2019 | |
| Income Taxes [Line Items] | |||
| Income (loss) before provision (benefit) for income taxes | $ 3,267 | $ 2,312 | $ (145) | 
| U.S. [Member] | |||
| Income Taxes [Line Items] | |||
| Income (loss) before provision (benefit) for income taxes | (602) | 2,405 | (256) | 
| Asia [Member] | |||
| Income Taxes [Line Items] | |||
| Income (loss) before provision (benefit) for income taxes | $ 3,869 | $ (93) | $ 111 | 
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- Definition Income taxes. No definition available. 
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- Definition Amount of income (loss) from continuing operations, including income (loss) from equity method investments, before deduction of income tax expense (benefit), and income (loss) attributable to noncontrolling interest. Reference 1: http://www.xbrl.org/2003/role/disclosureRef 
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