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Schedule II - Valuation and Qualifying Accounts (Detail) - USD ($) $ in Thousands | 12 Months Ended
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Mar. 31, 2020 | Mar. 31, 2019 | Mar. 31, 2018
Reserve for Doubtful Accounts Receivable [Member] |  |  |
Valuation and Qualifying Accounts Disclosure [Line Items] |  |  |
Balance at Beginning of Period | $ 33 | $ 339 | $ 168
Charged to Costs and Expenses |  | (167) | 177
Charged to Other Accounts |  | (13) |
Deductions |  | (126) | (6)
Balance at End of Period | 33 | 33 | 339
Product Warranty Liability [Member] |  |  |
Valuation and Qualifying Accounts Disclosure [Line Items] |  |  |
Balance at Beginning of Period | 366 | 493 | 538
Charged to Costs and Expenses | 62 | 234 | 527
Charged to Other Accounts |  | (85) |
Deductions | (69) | (276) | (572)
Balance at End of Period | $ 359 | 366 | 493
Restructuring Reserve [Member] |  |  |
Valuation and Qualifying Accounts Disclosure [Line Items] |  |  |
Balance at Beginning of Period |  | 18 | 120
Charged to Costs and Expenses |  |  | 316
Deductions |  | $ (18) | (418)
Balance at End of Period |  |  | $ 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) -URI http://asc.fasb.org/extlink&oid=26873400&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) -URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e24092-122690 + Details
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