Note 25 - Quarterly Financial Data (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	May 31, 2016	Feb. 28, 2016	Nov. 30, 2015	Aug. 31, 2015	May 31, 2015	Feb. 28, 2015	Nov. 30, 2014	Aug. 31, 2014	May 31, 2016	May 31, 2015	May 31, 2014
Net sales	$ 98,118	$ 88,893	$ 96,249	$ 96,712	$ 94,977	$ 95,605	$ 96,277	$ 102,441	$ 379,972	$ 389,300	$ 388,056
Gross Profit	60,809	54,763	58,361	62,070	57,889	61,634	60,504	65,614	236,003	245,641	248,422
Income (loss) from operations	3,123	5,093	8,188	12,510	8,170	12,878	8,351	13,874	28,914	43,273	(109,950)
Net Loss	(16,094)	(8,660)	(11,796)	(7,217)	$ (6,729)	$ (39,440)	$ (9,077)	$ (5,479)	(43,767)	(60,725)	(182,257)
Net loss attributable to noncontrolling interest	(1,440)	(237)							(1,677)
Net loss attributable to Immucor, Inc.	$ (14,654)	$ (8,423)	$ (11,796)	$ (7,217)					$ (42,090)	$ (60,725)	$ (182,257)