7. INCOME TAXES (Details 4) - USD ($) $ in Thousands	12 Months Ended
May 31, 2018	May 31, 2017	May 31, 2016
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Unrecognized tax benefit, Beginning	$ 789	$ 789	$ 919
Decreases related to prior year tax positions		0	(124)
Decreases related to lapse of statute of limitations		0	(6)
Increases related to prior year tax positions	889
Increases related to current year tax positions	107
Unrecognized tax benefit, Ending	$ 1,785	$ 789	$ 789

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

No definition available.

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Amount of unrecognized tax benefits.

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