Note 16 - Condensed Consolidating Financial Information Of Guarantor Subsidiary (Detail) - Condensed Consolidating Cash Flow Information (USD $) In Thousands, unless otherwise specified	3 Months Ended	6 Months Ended	9 Months Ended
Aug. 19, 2011	Feb. 29, 2012	Feb. 28, 2013	May 31, 2012	May 31, 2011
Net cash provided by (used in) operating activities	$ 25,588	$ (4,662)	$ (4,828)
Net cash used in investing activities	(2,265)	(1,942,673)	(6,915)
Net cash provided by ( used in) financing activities	66	1,653,627	12,543
Effect of exchange rate changes on cash and cash equivalents	(3,029)	(1,250)	142
Increase (decrease) in cash and cash equivalents	20,360	(294,958)	942
Cash and cash equivalents	322,963	28,005	19,520	18,578	302,603
Immucor Inc [Member] \| Beginning Balance [Member]
Cash and cash equivalents	250,386	314,304	8,093
Immucor Inc [Member] \| Ending Balance [Member]
Cash and cash equivalents	314,304	14,590	767
Immucor Inc [Member]
Net cash provided by (used in) operating activities	64,243	(11,674)	(16,071)
Net cash used in investing activities	(393)	(1,941,668)	(3,798)
Net cash provided by ( used in) financing activities	68	1,653,628	12,543
Increase (decrease) in cash and cash equivalents	63,918	(299,714)	(7,326)
Cash and cash equivalents			767	8,093
Guarantor [Member] \| Beginning Balance [Member]
Cash and cash equivalents	(80)	(89)	(144)
Guarantor [Member] \| Ending Balance [Member]
Cash and cash equivalents	(89)	(144)	(182)
Guarantor [Member]
Net cash provided by (used in) operating activities	144	310	2,464
Net cash used in investing activities	(153)	(365)	(2,502)
Increase (decrease) in cash and cash equivalents	(9)	(55)	(38)
Non-Guarantors [Member] \| Beginning Balance [Member]
Cash and cash equivalents	52,297	8,748	10,629
Non-Guarantors [Member] \| Ending Balance [Member]
Cash and cash equivalents	8,748	13,559	18,935
Non-Guarantors [Member]
Net cash provided by (used in) operating activities	(13,821)	16,680	8,691
Net cash used in investing activities	(1,719)	(640)	(615)
Net cash provided by ( used in) financing activities	(25,085)	(10,753)
Effect of exchange rate changes on cash and cash equivalents	(2,924)	(476)	231
Increase (decrease) in cash and cash equivalents	(43,549)	4,811	8,306
Cash and cash equivalents			18,935	10,629
Intersegment Elimination [Member]
Net cash provided by (used in) operating activities	(24,978)	(9,978)	88
Net cash provided by ( used in) financing activities	25,083	10,752
Effect of exchange rate changes on cash and cash equivalents	(105)	(774)	(88)
Cash and cash equivalents			(182)	(144)
Total [Member] \| Beginning Balance [Member]
Cash and cash equivalents	302,603	322,963	18,578
Total [Member] \| Ending Balance [Member]
Cash and cash equivalents	322,963	28,005	19,520
Total [Member]
Net cash provided by (used in) operating activities	25,588	(4,662)	(4,828)
Net cash used in investing activities	(2,265)	(1,942,673)	(6,915)
Net cash provided by ( used in) financing activities	66	1,653,627	12,543
Effect of exchange rate changes on cash and cash equivalents	(3,029)	(1,250)	142
Increase (decrease) in cash and cash equivalents	20,360	(294,958)	942
Cash and cash equivalents			$ 19,520	$ 18,578

Amount of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates. Excludes cash and cash equivalents within disposal group and discontinued operation.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section 45

-Paragraph 1

-Subparagraph (a)

-URI http://asc.fasb.org/extlink&oid=6361293&loc=d3e6676-107765

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Cash Equivalents

-URI http://asc.fasb.org/extlink&oid=6507016

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 95

-Paragraph 8, 9

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 95

-Paragraph 7, 26

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 5: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Cash

-URI http://asc.fasb.org/extlink&oid=6506951

Reference 6: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 4

-URI http://asc.fasb.org/extlink&oid=6943989&loc=d3e3044-108585

Reference 7: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 95

-Paragraph 7

-Footnote 1

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 8: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.1)

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 9: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 1

-Article 5

+ Details

- Definition

Amount of increase (decrease) in cash and cash equivalents. Cash and cash equivalents are the amount of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates. Excludes cash and cash equivalents within disposal group and discontinued operation.

+ References+ Details

- Definition

The net cash from (used in) all of the entity's operating activities, including those of discontinued operations, of the reporting entity. Operating activities generally involve producing and delivering goods and providing services. Operating activity cash flows include transactions, adjustments, and changes in value that are not defined as investing or financing activities. While for technical reasons this element has no balance attribute, the default assumption is a debit balance consistent with its label.

+ References+ Details