Note 15 - Segment and Geographic Information (Tables)

6 Months Ended

Nov. 30, 2013

Segment Reporting [Abstract]

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

	Three Months Ended				Six Months Ended
	November 30		November 30		November 30		November 30
	2013		2012		2013		2012
Net sales by product group:
Transfusion	$	85,559		80,362	$	168,549		163,931
Transplant & Molecular		14,644		1,694		27,698		3,279
Total	$	100,203		82,056	$	196,247		167,210

Export Sales to Unaffiliated Customers [Table Text Block]

	Three Months Ended
	November 30
	2013		2012
Net sales to customers by geography are as follows:
United States	$	61,416		52,968
Europe (A)		19,373		15,170
Canada		5,061		4,497
Other		14,353		9,421
Total	$	100,203		82,056

	Six Months Ended
	November 30
	2013		2012
Net sales to customers by geography are as follows:
United States	$	122,546		110,253
Europe (A)		37,289		30,039
Canada		9,614		9,574
Other		26,798		17,344
Total	$	196,247		167,210

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

	As of
	November 30, 2013		May 31, 2013
Long-lived tangible assets by geography:
United States	$	55,482		57,184
Europe (B)		14,445		13,399
Canada		4,524		4,511
Other (C)		1,783		1,287
Total	$	76,234		76,381

	As of
	November 30, 2013		May 31, 2013
Concentration of net assets by geography:
United States	$	481,862		485,968
Europe		115,907		114,740
Canada		32,730		32,910
Other (C)		11,170		11,088
Total	$	641,669		644,706