Note 16 - Condensed Consolidating Financial Information Of Guarantor Subsidiaries (Details) - Condensed Consolidating Statements of Operations (USD $) In Thousands, unless otherwise specified	3 Months Ended			6 Months Ended
	Nov. 30, 2013	Aug. 31, 2013	Nov. 30, 2012	Nov. 30, 2013	Nov. 30, 2012
Note 16 - Condensed Consolidating Financial Information Of Guarantor Subsidiaries (Details) - Condensed Consolidating Statements of Operations [Line Items]
NET SALES	$ 100,203		$ 82,056	$ 196,247	$ 167,210
OPERATING EXPENSES:
Acquisition-related items	(3,300)	(1,300)		(4,638)	0
NON-OPERATING INCOME (EXPENSE):
Interest expense	(22,093)		(22,251)	(44,271)	(46,739)
Loss on extinguishment of debt	(6,700)				(6,686)
NET (LOSS) INCOME BEFORE EARNINGS OF CONSOLIDATED SUBSIDIARIES				(8,547)	(21,034)
NET (LOSS) INCOME	(787)		(10,399)	(8,547)	(21,034)
Immucor Inc [Member]
Note 16 - Condensed Consolidating Financial Information Of Guarantor Subsidiaries (Details) - Condensed Consolidating Statements of Operations [Line Items]
NET SALES	65,161		61,454	129,372	125,958
COST OF SALES (exclusive of amortization shown separately below)	20,298		20,036	42,323	40,063
GROSS MARGIN	44,863		41,418	87,049	85,895
OPERATING EXPENSES:
Research and development	3,470		3,075	7,102	6,283
Selling and marketing	6,387		6,744	12,714	13,702
Distribution	2,679		2,935	5,402	5,810
General and administrative	3,986		8,080	10,853	15,629
Amortization of intangibles	11,971		11,771	23,942	23,542
Loss on disposition of fixed assets			1,175		1,175
Acquisition-related items	(3,318)			(4,638)
Total operating expenses	25,175		33,780	55,375	66,141
(LOSS) INCOME FROM OPERATIONS	19,688		7,638	31,674	19,754
NON-OPERATING INCOME (EXPENSE):
Interest income				1
Interest expense	(22,090)		(22,267)	(44,282)	(46,755)
Loss on extinguishment of debt					(6,686)
Other, net	(41)		(157)	(436)	(180)
Total non-operating (expense) income	(22,131)		(22,424)	(44,717)	(53,621)
(LOSS) INCOME BEFORE INCOME TAXES	(2,443)		(14,786)	(13,043)	(33,867)
(BENEFIT) PROVISION FOR INCOME TAXES	(1,322)		(3,894)	(5,268)	(10,979)
NET (LOSS) INCOME BEFORE EARNINGS OF CONSOLIDATED SUBSIDIARIES	(1,121)		(10,892)	(7,775)	(22,888)
Net (Loss) Income of consolidated subsidiaries	334		493	(772)	1,854
NET (LOSS) INCOME	(787)		(10,399)	(8,547)	(21,034)
Guarantor [Member]
Note 16 - Condensed Consolidating Financial Information Of Guarantor Subsidiaries (Details) - Condensed Consolidating Statements of Operations [Line Items]
NET SALES	14,090		1,462	27,754	2,903
COST OF SALES (exclusive of amortization shown separately below)	7,150		1,034	16,294	1,951
GROSS MARGIN	6,940		428	11,460	952
OPERATING EXPENSES:
Research and development	3,767		1,462	8,257	3,105
Selling and marketing	2,442		477	4,536	938
Distribution	373		44	755	87
General and administrative	2,165		400	3,900	874
Amortization of intangibles	666		54	1,334	108
Total operating expenses	9,413		2,437	18,782	5,112
(LOSS) INCOME FROM OPERATIONS	(2,473)		(2,009)	(7,322)	(4,160)
NON-OPERATING INCOME (EXPENSE):
Interest income				2
Other, net	44			72
Total non-operating (expense) income	44			74
(LOSS) INCOME BEFORE INCOME TAXES	(2,429)		(2,009)	(7,248)	(4,160)
(BENEFIT) PROVISION FOR INCOME TAXES	(839)		(853)	(2,454)	(1,565)
NET (LOSS) INCOME BEFORE EARNINGS OF CONSOLIDATED SUBSIDIARIES	(1,590)		(1,156)	(4,794)	(2,595)
NET (LOSS) INCOME	(1,590)		(1,156)	(4,794)	(2,595)
Non-Guarantors [Member]
Note 16 - Condensed Consolidating Financial Information Of Guarantor Subsidiaries (Details) - Condensed Consolidating Statements of Operations [Line Items]
NET SALES	37,963		30,383	72,953	59,989
COST OF SALES (exclusive of amortization shown separately below)	24,245		17,339	45,948	33,893
GROSS MARGIN	13,718		13,044	27,005	26,096
OPERATING EXPENSES:
Research and development	73			81	34
Selling and marketing	6,341		5,720	12,212	10,522
Distribution	1,785		1,742	3,399	3,332
General and administrative	2,126		2,333	4,500	4,426
Amortization of intangibles	578		579	1,146	1,135
Total operating expenses	10,903		10,374	21,338	19,449
(LOSS) INCOME FROM OPERATIONS	2,815		2,670	5,667	6,647
NON-OPERATING INCOME (EXPENSE):
Interest income	7		28	35	39
Interest expense	(7)		(5)	(15)	(13)
Other, net	17		(85)	169	58
Total non-operating (expense) income	17		(62)	189	84
(LOSS) INCOME BEFORE INCOME TAXES	2,832		2,608	5,856	6,731
(BENEFIT) PROVISION FOR INCOME TAXES	908		959	1,834	2,282
NET (LOSS) INCOME BEFORE EARNINGS OF CONSOLIDATED SUBSIDIARIES	1,924		1,649	4,022	4,449
NET (LOSS) INCOME	1,924		1,649	4,022	4,449
Eliminations [Member]
Note 16 - Condensed Consolidating Financial Information Of Guarantor Subsidiaries (Details) - Condensed Consolidating Statements of Operations [Line Items]
NET SALES	(17,011)		(11,243)	(33,832)	(21,640)
COST OF SALES (exclusive of amortization shown separately below)	(17,011)		(11,243)	(33,832)	(21,640)
NON-OPERATING INCOME (EXPENSE):
Interest income	(4)		(21)	(26)	(29)
Interest expense	4		21	26	29
Net (Loss) Income of consolidated subsidiaries	(334)		(493)	772	(1,854)
NET (LOSS) INCOME	(334)		(493)	772	(1,854)
Total [Member]
Note 16 - Condensed Consolidating Financial Information Of Guarantor Subsidiaries (Details) - Condensed Consolidating Statements of Operations [Line Items]
NET SALES	100,203		82,056	196,247	167,210
COST OF SALES (exclusive of amortization shown separately below)	34,682		27,166	70,733	54,267
GROSS MARGIN	65,521		54,890	125,514	112,943
OPERATING EXPENSES:
Research and development	7,310		4,537	15,440	9,422
Selling and marketing	15,170		12,941	29,462	25,162
Distribution	4,837		4,721	9,556	9,229
General and administrative	8,277		10,813	19,253	20,929
Amortization of intangibles	13,215		12,404	26,422	24,785
Loss on disposition of fixed assets			1,175		1,175
Acquisition-related items	(3,318)			(4,638)
Total operating expenses	45,491		46,591	95,495	90,702
(LOSS) INCOME FROM OPERATIONS	20,030		8,299	30,019	22,241
NON-OPERATING INCOME (EXPENSE):
Interest income	3		7	12	10
Interest expense	(22,093)		(22,251)	(44,271)	(46,739)
Loss on extinguishment of debt					(6,686)
Other, net	20		(242)	(195)	(122)
Total non-operating (expense) income	(22,070)		(22,486)	(44,454)	(53,537)
(LOSS) INCOME BEFORE INCOME TAXES	(2,040)		(14,187)	(14,435)	(31,296)
(BENEFIT) PROVISION FOR INCOME TAXES	(1,253)		(3,788)	(5,888)	(10,262)
NET (LOSS) INCOME BEFORE EARNINGS OF CONSOLIDATED SUBSIDIARIES	(787)		(10,399)	(8,547)	(21,034)
NET (LOSS) INCOME	$ (787)		$ (10,399)	$ (8,547)	$ (21,034)