Fair Value Disclosures (Tables)

12 Months Ended

May 31, 2018

Fair Value Disclosures [Abstract]

Summary of Financial Instruments Measured at Fair Value on a Recurring Basis

These financial instruments measured at fair value on a recurring basis are summarized below:

	As of May 31, 2018
(In thousands)	Level 1		Level 2		Level 3		Fair Value
Cash and cash equivalents	$	138,724	$	—	$	—	$	138,724
Total assets at fair value	$	138,724	$	—	$	—	$	138,724

	As of May 31, 2017
(In thousands)	Level 1		Level 2		Level 3		Fair Value
Cash and cash equivalents	$	169,266	$	—	$	—	$	169,266
Marketable securities:
Canadian treasury securities	—		22,219		—		22,219
Total assets at fair value	$	169,266	$	22,219	$	—	$	191,485