10. ACCUMULATED OTHER COMPREHENSIVE INCOME (Details) $ in Thousands	6 Months Ended
	Nov. 30, 2017 USD ($)
Accumulated other comprehensive income, beginning	$ 2,249	[1]
Other comprehensive income (loss) before reclassifications	57
Other comprehensive income (loss), net of tax	57
Accumulated other comprehensive income, ending	2,306
Accumulated Foreign Currency Adjustment Attributable to Parent [Member]
Accumulated other comprehensive income, beginning	2,249
Other comprehensive income (loss) before reclassifications	60
Other comprehensive income (loss), net of tax	60
Accumulated other comprehensive income, ending	2,309
Unrealized loss on Investments, Net
Accumulated other comprehensive income, beginning	0
Other comprehensive income (loss) before reclassifications	(3)
Other comprehensive income (loss), net of tax	(3)
Accumulated other comprehensive income, ending	$ (3)

[1] The condensed consolidated balance sheet at May 31, 2017 has been derived from the audited consolidated financial statements at that date.