3. CASH, CASH EQUIVALENTS AND INVESTMENTS (Tables)

12 Months Ended

May 31, 2018

Cash and Cash Equivalents [Abstract]

Cash, cash equivalents and investments by security type

    The following table summarizes the Company’s cash, cash equivalents and investments by security type at May 31, 2018 (in thousands):

	Cost		Gross Unrealized Loss		Estimated Fair Value
Cash	$	3,132	$	—	$	3,132
Cash equivalents:
Money market funds		7,733		—		7,733
U.S. Treasury securities		5,983		—		5,983
Total Cash equivalents		13,716		—		13,716
Total Cash and Cash equivalents	$	16,848	$	—	$	16,848
Long-term investments:
Certificate of deposit	$	80	$	—	$	80
Total Cash, Cash equivalents and Investments	$	16,928	$	—	$	16,928

    The following table summarizes the Company’s cash, cash equivalents and investments by security type at May 31, 2017 (in thousands):

	Cost		Gross Unrealized Loss		Estimated Fair Value
Cash	$	2,287	$	—	$	2,287
Cash equivalents:
Money market funds		15,516		—		15,516
Total Cash equivalents		15,516		—		15,516
Total Cash and Cash equivalents	$	17,803	$	—	$	17,803
Long-term investments:
Certificate of deposit	$	50	$	—	$	50
Total Cash, Cash equivalents and Investments	$	17,853	$	—	$	17,853