Note 15 - Segment and Geographic Information (Tables)

3 Months Ended

Aug. 31, 2013

Segment Reporting [Abstract]

Schedule of Segment Reporting Information, by Segment [Table Text Block]

	Three Months Ended
	August 31
	2013		2012
Net sales by product group:
Transfusion	$	82,990		83,570
Transplant & Molecular		13,054		1,584
Total	$	96,044		85,154

Export Sales to Unaffiliated Customers [Table Text Block]

	Three Months Ended
	August 31
	2013		2012
Net sales to customers by geography are as follows:
United States	$	61,120		57,825
Europe (A)		17,851		14,869
Canada		4,553		5,078
Other		12,520		7,382
Total	$	96,044		85,154

Schedule of Revenue from External Customers and Long-Lived Assets, by Geographical Areas [Table Text Block]

	As of
	August 31, 2013		May 31, 2013
Long-lived tangible assets by geography:
United States	$	55,171		57,184
Europe (B)		14,152		13,399
Canada		4,446		4,511
Other (C)		1,571		1,287
Total	$	75,340		76,381

	As of
	August 31, 2013		May 31, 2013
Concentration of net assets by geography:
United States	$	484,416		485,968
Europe		110,668		114,740
Canada		32,564		32,910
Other (C)		11,455		11,088
Total	$	639,103		644,706