Summary of Significant Accounting Policies - Going concern thru intangibles (Detail) - USD ($) |
12 Months Ended | ||
|---|---|---|---|
May 31, 2021 |
May 31, 2020 |
May 31, 2019 |
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| Accounting Policies [Abstract] | |||
| Net loss | $ 154,674,000 | $ 124,403,000 | $ 56,187,000 |
| Accumulated deficit | 511,294,000 | 354,711,000 | |
| Balance in excess of federally insured limits | 33,700,000 | 14,000,000.0 | |
| Restricted cash | 10,000 | 854,000 | |
| Intangible asset impairment charges | $ 0 | $ 0 | $ 0 |
| X | ||||||||||
- References No definition available.
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| X | ||||||||||
- Definition The amount of cash as of the balance sheet date that is not insured by the Federal Deposit Insurance Corporation. No definition available.
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- Definition The amount of impairment loss recognized in the period resulting from the write-down of the carrying amount of a finite-lived intangible asset to fair value. Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
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| X | ||||||||||
- Definition The portion of profit or loss for the period, net of income taxes, which is attributable to the parent. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition Amount of cash and cash equivalents restricted as to withdrawal or usage, classified as current. Cash includes, but is not limited to, currency on hand, demand deposits with banks or financial institutions, and other accounts with general characteristics of demand deposits. Cash equivalents include, but are not limited to, short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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| X | ||||||||||
- Definition The cumulative amount of the reporting entity's undistributed earnings or deficit. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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