Note 3 - Consolidated Variable Interest Entity - Components of Assets and Liabilities of Variable Interest Entities (Details) - USD ($) $ in Thousands	Nov. 30, 2016	May 31, 2016	Nov. 30, 2015	May 31, 2015
Cash and cash equivalents	$ 10,488	$ 10,263	$ 15,067	$ 18,363
Accounts payable	17,398	22,229
Total current assets	125,299	127,679
Total current liabilities	80,742	75,362
Property and equipment, net	76,310	76,015
Deferred income tax liabilities	207,603	222,357
Goodwill	854,416	857,023		842,258
Obligation to Immucor for contingent consideration liabilities	42,344	40,356		$ 18,596
Total noncurrent assets	76,310	76,015
Total assets	1,670,094	1,707,633
Total liabilities	1,352,152	1,363,087
Sentilus [Member]
Cash and cash equivalents	8	36
Accounts payable	436	744
Total current assets	8	36
Accrued expenses and other current liabilities	15	4
Total current liabilities	451	748
Property and equipment, net	661	644
Deferred income tax liabilities	4,581	6,207
Goodwill	105	105
Other intangible assets, net	18,817	18,820
Obligation to Immucor for contingent consideration liabilities	7,819	7,433
Total noncurrent assets	19,583	19,569
Total noncurrent liabilities	12,400	13,640
Total assets	19,591	19,605
Total liabilities	$ 12,851	$ 14,388