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Schedule II - Valuation and Qualifying Accounts (Detail) - USD ($) $ in Thousands | 12 Months Ended
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Mar. 31, 2021 | Mar. 31, 2020 | Mar. 31, 2019
Reserve for Doubtful Accounts Receivable [Member] |  |  |
Valuation and Qualifying Accounts Disclosure [Line Items] |  |  |
Balance at Beginning of Period | $ 33 | $ 33 | $ 339
Charged to Costs and Expenses | (4) |  | (167)
Charged to Other Accounts |  |  | (13)
Deductions |  |  | (126)
Balance at End of Period | 29 | 33 | 33
Product Warranty Liability [Member] |  |  |
Valuation and Qualifying Accounts Disclosure [Line Items] |  |  |
Balance at Beginning of Period | 359 | 366 | 493
Charged to Costs and Expenses | 344 | 62 | 234
Charged to Other Accounts |  |  | (85)
Deductions | (77) | (69) | (276)
Balance at End of Period | $ 626 | $ 359 | 366
Restructuring Reserve [Member] |  |  |
Valuation and Qualifying Accounts Disclosure [Line Items] |  |  |
Balance at Beginning of Period |  |  | 18
Deductions |  |  | $ (18)

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- Definition Amount of valuation and qualifying accounts and reserves. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 235 -SubTopic 10 -Section S99 -Paragraph 4 -Subparagraph (SX 210.12-09(Column B)) -URI http://asc.fasb.org/extlink&oid=120395691&loc=d3e24092-122690 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 235 -SubTopic 10 -Section S99 -Paragraph 4 -Subparagraph (SX 210.12-09(Column E)) -URI http://asc.fasb.org/extlink&oid=120395691&loc=d3e24092-122690 + Details
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- Definition Amount of increase in valuation and qualifying accounts and reserves from charge to cost and expense. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 235 -SubTopic 10 -Section S99 -Paragraph 4 -Subparagraph (SX 210.12-09(Column C)(1)) -URI http://asc.fasb.org/extlink&oid=120395691&loc=d3e24092-122690 + Details
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- Definition Amount of increase in valuation and qualifying accounts and reserves from charge to accounts other than cost and expense. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 235 -SubTopic 10 -Section S99 -Paragraph 4 -Subparagraph (SX 210.12-09(Column C)(2)) -URI http://asc.fasb.org/extlink&oid=120395691&loc=d3e24092-122690 + Details
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- Definition Amount of decrease in valuation and qualifying accounts and reserves. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 235 -SubTopic 10 -Section S99 -Paragraph 4 -Subparagraph (SX 210.12-09(Column D)) -URI http://asc.fasb.org/extlink&oid=120395691&loc=d3e24092-122690 + Details
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