Income Taxes (Details 2)	12 Months Ended
May 31, 2020	May 31, 2019
Income Tax Disclosure [Abstract]
Statutory federal rate	21.00%	21.00%
State taxes, net of federal benefit	5.30%	5.30%
Change in deferred tax valuation allowance	(27.10%)	(25.70%)
Impact of Tax Act	0.00%	0.00%
Stock-based compensation	0.00%	(1.80%)
R&E tax credits	0.20%	1.80%
Effect of foreign income tax rates	(0.10%)	(3.40%)
Deferred tax true-up	0.00%	4.10%
State minimum taxes	1.70%	(1.00%)
Permanent and other differences	0.20%	(2.50%)
Effective tax rate	1.20%	(2.20%)

Effective income tax rate reconciliation deferred tax true up.

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Effective income tax rate reconciliation permanent differences.

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Percentage of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

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-Name Accounting Standards Codification
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Percentage of domestic federal statutory tax rate applicable to pretax income (loss).

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Percentage of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations attributable to changes in the valuation allowance for deferred tax assets.

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Percentage of difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying domestic federal statutory income tax rate to pretax income (loss) from continuing operation, attributable to nondeductible expense for share-based payment arrangement.

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Percentage of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations applicable to state and local income tax expense (benefit), net of federal tax expense (benefit).

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