Goodwill and Intangibles - Changes in Carrying Amount of Goodwill and Other Intangible Assets (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Aug. 31, 2014	Aug. 31, 2013
Goodwill [Roll Forward]
Balance as of June 1, 2014 (net of amortization)	$ 3,109
Additions	0
Balance as of August 31, 2014	3,109
Customer Relationships [Roll Forward]
Amortization	(41)	(41)
Balance as of August 31, 2014	421
Goodwill and Other Intangible Assets [Roll Forward]
Balance as of June 1, 2014 (net of amortization)	3,982
Additions	0
Amortization	(41)	(41)
Balance as of August 31, 2014	3,941
Customer relationships
Customer Relationships [Roll Forward]
Balance as of June 1, 2014 (net of amortization)	462
Additions	0
Amortization	(41)
Balance as of August 31, 2014	421
Goodwill and Other Intangible Assets [Roll Forward]
Amortization	(41)
Trade name
Trade Name [Roll Forward]
Balance as of June 1, 2014 (net of amortization)	411
Additions	0
Balance as of August 31, 2014	$ 411