Note 16 - Condensed Consolidating Financial Information Of Guarantor Subsidiary (Detail) - Condensed Consolidating Statements of Operations (USD $)	3 Months Ended			6 Months Ended	9 Months Ended
	Feb. 28, 2013	Feb. 29, 2012	Aug. 19, 2011	Feb. 29, 2012	Feb. 28, 2013
NET SALES	$ 86,192,000	$ 81,370,000	$ 74,910,000	$ 175,795,000	$ 253,402,000
COST OF SALES (exclusive of amortization shown separately below)	29,997,000	28,588,000	22,955,000	78,170,000	84,264,000
GROSS MARGIN	56,195,000	52,782,000	51,955,000	97,625,000	169,138,000
OPERATING EXPENSES:
Research and development	4,854,000	3,775,000	4,895,000	9,544,000	14,276,000
Selling and marketing	11,056,000	9,608,000	10,510,000	20,653,000	36,218,000
Distribution	4,588,000	4,496,000	3,952,000	9,721,000	13,817,000
General and administrative	10,446,000	13,396,000	38,175,000	25,355,000	31,375,000
Amortization of intangibles	12,407,000	12,394,000	931,000	26,504,000	37,192,000
Total operating expenses	43,351,000	43,669,000	58,463,000	113,777,000	134,053,000
Loss on disposition of fixed assets					(1,175,000)
Certain litigation expenses				22,000,000
INCOME (LOSS) FROM OPERATIONS	12,844,000	9,113,000	(6,508,000)	(16,152,000)	35,085,000
NON-OPERATING INCOME (EXPENSE):
Interest income	12,000		142,000	6,000	22,000
Interest expense	21,952,000	24,143,000		52,386,000	68,691,000
Loss on extinguishment of debt	(2,425,000)				(9,111,000)
Other, net	(143,000)	(60,000)	2,673,000	600,000	(265,000)
Total non-operating income (expense)	(24,508,000)	(24,203,000)	2,815,000	(51,780,000)	(78,045,000)
INCOME (LOSS) BEFORE INCOME TAXES	(11,664,000)	(15,090,000)	(3,693,000)	(67,932,000)	(42,960,000)
PROVISION (BENEFIT) FOR INCOME TAXES	(5,751,000)	(5,959,000)	2,681,000	(26,180,000)	(16,013,000)
NET INCOME (LOSS) BEFORE EARNINGS OF CONSOLIDATED SUBSIDIARIES	(5,913,000)	(9,131,000)	(6,374,000)	(41,752,000)	(26,947,000)
NET INCOME (LOSS)	(5,913,000)	(9,131,000)	(6,374,000)	(41,752,000)	(26,947,000)
Immucor Inc [Member]
NET SALES	66,455,000	58,374,000	55,063,000	125,296,000	192,414,000
COST OF SALES (exclusive of amortization shown separately below)	21,797,000	19,633,000	17,070,000	52,294,000	61,860,000
GROSS MARGIN	44,658,000	38,741,000	37,993,000	73,002,000	130,554,000
OPERATING EXPENSES:
Research and development	3,539,000	2,285,000	2,390,000	4,671,000	9,822,000
Selling and marketing	5,575,000	5,146,000	5,321,000	10,702,000	19,277,000
Distribution	2,843,000	2,691,000	2,331,000	5,847,000	8,653,000
General and administrative	7,583,000	9,961,000	33,903,000	18,263,000	23,213,000
Amortization of intangibles	11,770,000	11,251,000	117,000	23,982,000	35,312,000
Total operating expenses	31,310,000	31,334,000	44,062,000	85,465,000	97,452,000
Loss on disposition of fixed assets					1,175,000
Certain litigation expenses				22,000,000
INCOME (LOSS) FROM OPERATIONS	13,348,000	7,407,000	(6,069,000)	(12,463,000)	33,102,000
NON-OPERATING INCOME (EXPENSE):
Interest income			46,000
Interest expense	(21,970,000)	(24,143,000)		(52,406,000)	(68,726,000)
Loss on extinguishment of debt	(2,425,000)				(9,111,000)
Other, net	(139,000)	(94,000)	(246,000)	513,000	(319,000)
Total non-operating income (expense)	(24,534,000)	(24,237,000)	(200,000)	(51,893,000)	(78,156,000)
INCOME (LOSS) BEFORE INCOME TAXES	(11,186,000)	(16,830,000)	(6,269,000)	(64,356,000)	(45,054,000)
PROVISION (BENEFIT) FOR INCOME TAXES	(5,570,000)	(6,670,000)	1,497,000	(24,831,000)	(16,549,000)
NET INCOME (LOSS) BEFORE EARNINGS OF CONSOLIDATED SUBSIDIARIES	(5,616,000)	(10,160,000)	(7,766,000)	(39,525,000)	(28,505,000)
Net Income (Loss) of consolidated subsidiaries	(297,000)	1,029,000	1,392,000	(2,227,000)	1,558,000
NET INCOME (LOSS)	(5,913,000)	(9,131,000)	(6,374,000)	(41,752,000)	(26,947,000)
Guarantor [Member]
NET SALES	1,450,000	1,368,000	980,000	2,868,000	4,353,000
COST OF SALES (exclusive of amortization shown separately below)	1,046,000	1,049,000	722,000	2,644,000	2,997,000
GROSS MARGIN	404,000	319,000	258,000	224,000	1,356,000
OPERATING EXPENSES:
Research and development	1,315,000	1,466,000	2,471,000	4,810,000	4,419,000
Selling and marketing	458,000	431,000	568,000	1,040,000	1,396,000
Distribution	57,000	43,000	34,000	84,000	144,000
General and administrative	444,000	486,000	657,000	1,138,000	1,319,000
Amortization of intangibles	54,000	50,000	757,000	106,000	163,000
Total operating expenses	2,328,000	2,476,000	4,487,000	7,178,000	7,441,000
INCOME (LOSS) FROM OPERATIONS	(1,924,000)	(2,157,000)	(4,229,000)	(6,954,000)	(6,085,000)
NON-OPERATING INCOME (EXPENSE):
Other, net			14,000
Total non-operating income (expense)			14,000
INCOME (LOSS) BEFORE INCOME TAXES	(1,924,000)	(2,157,000)	(4,215,000)	(6,954,000)	(6,085,000)
PROVISION (BENEFIT) FOR INCOME TAXES	(695,000)	(921,000)	(1,598,000)	(2,653,000)	(2,260,000)
NET INCOME (LOSS) BEFORE EARNINGS OF CONSOLIDATED SUBSIDIARIES	(1,229,000)	(1,236,000)	(2,617,000)	(4,301,000)	(3,825,000)
NET INCOME (LOSS)	(1,229,000)	(1,236,000)	(2,617,000)	(4,301,000)	(3,825,000)
Non-Guarantors [Member]
NET SALES	30,123,000	29,954,000	26,648,000	64,808,000	90,112,000
COST OF SALES (exclusive of amortization shown separately below)	18,990,000	16,232,000	12,944,000	40,409,000	52,884,000
GROSS MARGIN	11,133,000	13,722,000	13,704,000	24,399,000	37,228,000
OPERATING EXPENSES:
Research and development		24,000	34,000	63,000	35,000
Selling and marketing	5,023,000	4,031,000	4,621,000	8,911,000	15,545,000
Distribution	1,688,000	1,762,000	1,587,000	3,790,000	5,020,000
General and administrative	2,419,000	2,949,000	3,615,000	5,954,000	6,843,000
Amortization of intangibles	583,000	1,093,000	57,000	2,416,000	1,717,000
Total operating expenses	9,713,000	9,859,000	9,914,000	21,134,000	29,160,000
INCOME (LOSS) FROM OPERATIONS	1,420,000	3,863,000	3,790,000	3,265,000	8,068,000
NON-OPERATING INCOME (EXPENSE):
Interest income	35,000	19,000	117,000	73,000	74,000
Interest expense	(5,000)	(19,000)	(21,000)	(47,000)	(17,000)
Other, net	(4,000)	34,000	2,905,000	87,000	54,000
Total non-operating income (expense)	26,000	34,000	3,001,000	113,000	111,000
INCOME (LOSS) BEFORE INCOME TAXES	1,446,000	3,897,000	6,791,000	3,378,000	8,179,000
PROVISION (BENEFIT) FOR INCOME TAXES	514,000	1,632,000	2,782,000	1,304,000	2,796,000
NET INCOME (LOSS) BEFORE EARNINGS OF CONSOLIDATED SUBSIDIARIES	932,000	2,265,000	4,009,000	2,074,000	5,383,000
NET INCOME (LOSS)	932,000	2,265,000	4,009,000	2,074,000	5,383,000
Intersegment Elimination [Member]
NET SALES	(11,836,000)	(8,326,000)	(7,781,000)	(17,177,000)	(33,477,000)
COST OF SALES (exclusive of amortization shown separately below)	(11,836,000)	(8,326,000)	(7,781,000)	(17,177,000)	(33,477,000)
NON-OPERATING INCOME (EXPENSE):
Interest income	(23,000)	(19,000)	(21,000)	(67,000)	(52,000)
Interest expense	23,000	19,000	21,000	67,000	52,000
Net Income (Loss) of consolidated subsidiaries	297,000	(1,029,000)	(1,392,000)	2,227,000	(1,558,000)
NET INCOME (LOSS)	297,000	(1,029,000)	(1,392,000)	2,227,000	(1,558,000)
Total [Member]
NET SALES	86,192,000	81,370,000	74,910,000	175,795,000	253,402,000
COST OF SALES (exclusive of amortization shown separately below)	29,997,000	28,588,000	22,955,000	78,170,000	84,264,000
GROSS MARGIN	56,195,000	52,782,000	51,955,000	97,625,000	169,138,000
OPERATING EXPENSES:
Research and development	4,854,000	3,775,000	4,895,000	9,544,000	14,276,000
Selling and marketing	11,056,000	9,608,000	10,510,000	20,653,000	36,218,000
Distribution	4,588,000	4,496,000	3,952,000	9,721,000	13,817,000
General and administrative	10,446,000	13,396,000	38,175,000	25,355,000	31,375,000
Amortization of intangibles	12,407,000	12,394,000	931,000	26,504,000	37,192,000
Total operating expenses	43,351,000	43,669,000	58,463,000	113,777,000	134,053,000
Loss on disposition of fixed assets					1,175,000
Certain litigation expenses				22,000,000
INCOME (LOSS) FROM OPERATIONS	12,844,000	9,113,000	(6,508,000)	(16,152,000)	35,085,000
NON-OPERATING INCOME (EXPENSE):
Interest income	12,000		142,000	6,000	22,000
Interest expense	(21,952,000)	(24,143,000)		(52,386,000)	(68,691,000)
Loss on extinguishment of debt	(2,425,000)				(9,111,000)
Other, net	(143,000)	(60,000)	2,673,000	600,000	(265,000)
Total non-operating income (expense)	(24,508,000)	(24,203,000)	2,815,000	(51,780,000)	(78,045,000)
INCOME (LOSS) BEFORE INCOME TAXES	(11,664,000)	(15,090,000)	(3,693,000)	(67,932,000)	(42,960,000)
PROVISION (BENEFIT) FOR INCOME TAXES	(5,751,000)	(5,959,000)	2,681,000	(26,180,000)	(16,013,000)
NET INCOME (LOSS) BEFORE EARNINGS OF CONSOLIDATED SUBSIDIARIES	(5,913,000)	(9,131,000)	(6,374,000)	(41,752,000)	(26,947,000)
NET INCOME (LOSS)	$ (5,913,000)	$ (9,131,000)	$ (6,374,000)	$ (41,752,000)	$ (26,947,000)