| License Agreements - Additional Information (Detail) | Aug. 31, 2018  USD ($) | May 31, 2018  USD ($) | Mar. 15, 2018  USD ($) | Mar. 15, 2018  GBP (£) | 
|---|---|---|---|---|
| Licenses Agreements [Line Items] | ||||
| Accrued license fee | $ 233,800 | $ 133,600 | $ 400,000 | £ 300,000 | 
| Minimum | ||||
| Licenses Agreements [Line Items] | ||||
| Royalty on every net sales | 0.75% | |||
| Maximum | ||||
| Licenses Agreements [Line Items] | ||||
| Royalty on every net sales | 2.00% | 
| X | ||||||||||
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- Definition Accrued license fees current. No definition available. 
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| X | ||||||||||
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- Definition Licenses Agreements [Line Items] No definition available. 
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| X | ||||||||||
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- Definition Potential royalty payment as percentage of net sales. No definition available. 
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| X | ||||||||||
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- Details 
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| X | ||||||||||
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- Details 
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