Investments - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Aug. 30, 2014	Aug. 31, 2013	May 31, 2014
Investment [Line Items]
Investment in time deposits and certificate of deposits	$ 34.6		$ 32.7
Investment in time deposits and certificate of deposits, less than twelve months	26.4		31.7
Investment in time deposits and certificate of deposits, greater than twelve months	8.2		1.0
Investments, which are included in non-current assets	$ 0.5		$ 0.5
Proceeds from the sale of securities description	less than $0.1 million	0.1
Gross realized gains and losses on sale, description	less than $0.1 million	less than $0.1
Net unrealized holding gains, description	less than $0.1 million	less than $0.1