Note 19 - Segment and Geographic Information (Details) - Sales by Product Group (USD $) In Thousands, unless otherwise specified	3 Months Ended									9 Months Ended	12 Months Ended
	May 31, 2014	Feb. 28, 2014	Nov. 30, 2013	Aug. 31, 2013	May 31, 2013	Feb. 28, 2013	Nov. 30, 2012	Aug. 31, 2012	Aug. 19, 2011	May 31, 2012	May 31, 2014	May 31, 2013
Net sales by product group:
Net sales by product group	$ 100,830	$ 90,979	$ 100,203	$ 96,044	$ 94,386	$ 86,192	$ 82,056	$ 85,154	$ 74,910	$ 261,814	$ 388,056	$ 347,788
Transfusion [Member]
Net sales by product group:
Net sales by product group									73,632	257,046	330,547	330,931
Transplant & Molecular [Member]
Net sales by product group:
Net sales by product group									$ 1,278	$ 4,768	$ 57,509	$ 16,857