Note 14 - Segment and Geographic Information (Detail) - Sales by Product Group (USD $) In Thousands, unless otherwise specified	0 Months Ended	3 Months Ended
	Aug. 31, 2011	Aug. 31, 2012	Aug. 19, 2011
Sales by product group	$ 11,390	$ 85,154	$ 74,910
Traditional Reagents [Member]
Sales by product group	6,296	47,047	42,936
Capture Reagents [Member]
Sales by product group	3,254	24,313	21,239
Instruments [Member]
Sales by product group	1,619	12,210	9,457
Molecular Immunohematology [Member]
Sales by product group	$ 221	$ 1,584	$ 1,278