Note 6 - Property and Equipment, Net (Details) - Property and Equipment (USD $) In Thousands, unless otherwise specified	May 31, 2014	May 31, 2013
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 123,589	$ 107,314
Less accumulated depreciation	(47,278)	(30,933)
Property and equipment, net	76,311	76,381
Land [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	290	301
Building and Building Improvements [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	2,966	3,034
Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	24,693	20,170
Construction in Progress [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	3,927	5,139
Furniture and Fixtures [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	3,656	3,282
Machinery and Equipment [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 88,057	$ 75,388