Note 2 - Business Combinations (Details) - Intangible Assets Acquired (USD $) In Thousands, unless otherwise specified	12 Months Ended
	May 31, 2013
LIFECODES [Member] | Customer Relationships [Member]
Note 2 - Business Combinations (Details) - Intangible Assets Acquired [Line Items]
Fair Value	$ 16,000
Useful Life in Years	20 years
LIFECODES [Member] | Existing Technology [Member]
Note 2 - Business Combinations (Details) - Intangible Assets Acquired [Line Items]
Fair Value	13,250
Useful Life in Years	10 years
LIFECODES [Member] | Trade Names [Member]
Note 2 - Business Combinations (Details) - Intangible Assets Acquired [Line Items]
Fair Value	2,250
Useful Life in Years	22 years
LIFECODES [Member] | Below market leasehold interests [Member]
Note 2 - Business Combinations (Details) - Intangible Assets Acquired [Line Items]
Fair Value	340
LIFECODES [Member] | In Process Research and Development [Member]
Note 2 - Business Combinations (Details) - Intangible Assets Acquired [Line Items]
Fair Value	1,400
LIFECODES [Member]
Note 2 - Business Combinations (Details) - Intangible Assets Acquired [Line Items]
	33,240
Immucor Inc [Member] | Customer Relationships [Member]
Note 2 - Business Combinations (Details) - Intangible Assets Acquired [Line Items]
Fair Value	455,000
Useful Life in Years	20 years
Immucor Inc [Member] | Existing Technology [Member]
Note 2 - Business Combinations (Details) - Intangible Assets Acquired [Line Items]
Fair Value	266,000
Useful Life in Years	11 years
Immucor Inc [Member] | Trade Names [Member]
Note 2 - Business Combinations (Details) - Intangible Assets Acquired [Line Items]
Fair Value	40,000
Useful Life in Years	15 years
Immucor Inc [Member] | Below market leasehold interests [Member]
Note 2 - Business Combinations (Details) - Intangible Assets Acquired [Line Items]
Fair Value	860
Useful Life in Years	5 years
Immucor Inc [Member] | In Process Research and Development [Member]
Note 2 - Business Combinations (Details) - Intangible Assets Acquired [Line Items]
Fair Value	18,000
Immucor Inc [Member]
Note 2 - Business Combinations (Details) - Intangible Assets Acquired [Line Items]
	$ 779,860
Below market leasehold interests [Member]
Note 2 - Business Combinations (Details) - Intangible Assets Acquired [Line Items]
Useful Life in Years	6 years
Minimum [Member] | LIFECODES [Member] | Below market leasehold interests [Member]
Note 2 - Business Combinations (Details) - Intangible Assets Acquired [Line Items]
Useful Life in Years	2 years
Maximum [Member] | LIFECODES [Member] | Below market leasehold interests [Member]
Note 2 - Business Combinations (Details) - Intangible Assets Acquired [Line Items]
Useful Life in Years	12 years