Debt Agreement - Additional Information (Detail) - USD ($)		3 Months Ended
	Nov. 30, 2012	May. 30, 2015
Debt Disclosure [Line Items]
Revolving credit facility commitment fee description		The Amended Credit Agreement pricing grid is adjusted quarterly and is based on the Company’s leverage ratio (as defined in the Amended Credit Agreement). The minimum pricing is LIBOR plus 0.90% or Base Rate (as defined in the Amended Credit Agreement) and the maximum pricing is LIBOR plus 1.75% or Base Rate (as defined in the Amended Credit Agreement) plus 0.75%. The Company is subject to an unused commitment fee based on the Company’s leverage ratio with minimum pricing of 0.10% and maximum pricing of 0.25%. In addition, the Company is subject to a letter of credit fee based on the Company’s leverage ratio with minimum pricing of 0.40% and maximum pricing of 1.25%.
Minimum
Debt Disclosure [Line Items]
LIBOR rate		0.90%
Commitment fee percentage		0.10%
Letter of credit fee percentage		0.40%
Maximum
Debt Disclosure [Line Items]
LIBOR rate		1.75%
Base rate		0.75%
Commitment fee percentage		0.25%
Letter of credit fee percentage		1.25%
Amended Credit Agreement
Debt Disclosure [Line Items]
Unsecured revolving credit facility, maximum borrowing capacity	$ 100,000,000
Revolving credit facility agreement, expiration date	Nov. 30, 2017
Increase in credit facility maximum borrowing capacity	$ 200,000,000
Stand-by letters of credit outstanding		$ 2,200,000
Revolving credit facility available for borrowing		$ 97,800,000