Fair Value Measurements (Tables)

9 Months Ended

Feb. 28, 2017

Fair Value Disclosures [Abstract]

Schedule of Fair Value of Financial Instruments Measured on a Recurring Basis

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

	As of February 28, 2017
(In thousands)	Level 1		Level 2		Level 3		Fair Value
Cash and cash equivalents	$	147,244	$	—	$	—	$	147,244
Prepaid expenses and other current assets:
Interest rate lock agreements	—		7,346		—		7,346
Total assets at fair value	$	147,244	$	7,346	$	—	$	154,590

	As of May 31, 2016
(In thousands)	Level 1		Level 2		Level 3		Fair Value
Cash and cash equivalents	$	139,357	$	—	$	—	$	139,357
Marketable securities:
Canadian treasury securities	—		70,405		—		70,405
Total assets at fair value	$	139,357	$	70,405	$	—	$	209,762
Long-term accrued liabilities:
Interest rate lock agreements	$	—	$	19,628	$	—	$	19,628
Total liabilities at fair value	$	—	$	19,628	$	—	$	19,628