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Summary of Significant Accounting Policies - Schedule of Employee Service Share-based Compensation, Allocation of Recognized Period Costs (Details) - USD ($) $ in Thousands | 3 Months Ended | 6 Months Ended
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Oct. 31, 2020 | Oct. 31, 2019 | Oct. 31, 2020 | Oct. 31, 2019
Total share-based compensation expense | $ 107 | $ 76 | $ 223 | $ 168
Engineering and Product Development [Member] |  |  |  |
Total share-based compensation expense | 22 | 20 | 59 | 40
Selling, General and Administrative [Member] |  |  |  |
Total share-based compensation expense | $ 85 | $ 56 | $ 164 | $ 128

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- Definition Amount of noncash expense for share-based payment arrangement. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 28 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=121586364&loc=d3e3602-108585 + Details
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- Details
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- Details
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