Note 16 - Condensed Consolidating Financial Information Of Guarantor Subsidiary (Detail) - Condensed Consolidating Balance Sheets (USD $) In Thousands, unless otherwise specified	Feb. 28, 2013	May 31, 2012	Feb. 29, 2012	Aug. 19, 2011	May 31, 2011
CURRENT ASSETS:
Cash and cash equivalents	$ 19,520	$ 18,578	$ 28,005	$ 322,963	$ 302,603
Accounts receivable, net	65,390	66,392
Inventories	35,615	33,370
Deferred income tax assets, current portion	5,632	5,489
Prepaid expenses and other current assets	10,752	11,738
Total current assets	136,909	135,567
PROPERTY AND EQUIPMENT, Net	64,264	64,662
GOODWILL	967,218	966,338
INTANGIBLE ASSETS, Net	699,037	735,522
DEFERRED FINANCING COSTS	39,411	38,769
OTHER ASSETS	6,731	8,295
Total assets	1,913,570	1,949,153
CURRENT LIABILITIES:
Accounts payable	12,969	12,734
Income taxes payable	4,124	3,654
Deferred revenue, current portion	2,389	2,606
Current portion of long term debt, net of debt discounts	25,210	3,922
Total current liabilities	65,117	64,272
LONG TERM DEBT, NET OF DEBT DISCOUNTS	992,783	986,361
DEFERRED REVENUE	320	431
DEFERRED INCOME TAX LIABILITIES	227,034	245,496
OTHER LONG-TERM LIABILITIES	12,551	15,215
Total liabilities	1,297,805	1,311,775
SHAREHOLDERS' EQUITY
Total shareholders’ equity	615,765	637,378
Total liabilities and shareholders’ equity	1,913,570	1,949,153
Immucor Inc [Member]
CURRENT ASSETS:
Cash and cash equivalents	767	8,093
Accounts receivable, net	31,248	27,542
Intercompany receivable	51,508	46,856
Inventories	21,971	21,697
Deferred income tax assets, current portion	4,168	4,168
Prepaid expenses and other current assets	5,320	6,336
Total current assets	114,982	114,692
PROPERTY AND EQUIPMENT, Net	41,574	44,103
INVESTMENT IN SUBSIDIARIES	168,717	162,895
GOODWILL	903,512	903,512
INTANGIBLE ASSETS, Net	646,745	682,187
DEFERRED FINANCING COSTS	39,411	38,769
OTHER ASSETS	6,231	7,817
Total assets	1,921,172	1,953,975
CURRENT LIABILITIES:
Accounts payable	8,894	9,816
Intercompany payable	1,015	190
Accrued expenses and other current liabilities	11,284	31,250
Income taxes payable	30,724	30,719
Deferred revenue, current portion	1,223	1,270
Current portion of long term debt, net of debt discounts	25,210	3,922
Total current liabilities	78,350	77,167
LONG TERM DEBT, NET OF DEBT DISCOUNTS	992,783	986,361
DEFERRED REVENUE	296	391
DEFERRED INCOME TAX LIABILITIES	222,637	238,582
OTHER LONG-TERM LIABILITIES	11,341	14,096
Total liabilities	1,305,407	1,316,597
SHAREHOLDERS' EQUITY
Total shareholders’ equity	615,765	637,378
Total liabilities and shareholders’ equity	1,921,172	1,953,975
Guarantor [Member]
CURRENT ASSETS:
Accounts receivable, net	876	489
Intercompany receivable	9	23
Inventories	2,615	1,438
Deferred income tax assets, current portion	531	531
Prepaid expenses and other current assets	31,408	31,227
Total current assets	35,439	33,708
PROPERTY AND EQUIPMENT, Net	3,649	1,407
GOODWILL	6,659	6,659
INTANGIBLE ASSETS, Net	10,276	10,438
OTHER ASSETS	7,818	5,558
Total assets	63,841	57,770
CURRENT LIABILITIES:
Accounts payable	1,218	1,145
Intercompany payable	49,047	39,177
Accrued expenses and other current liabilities	1,381	1,421
Income taxes payable	4
Deferred revenue, current portion	10	20
Total current liabilities	51,660	41,763
Total liabilities	51,660	41,763
SHAREHOLDERS' EQUITY
Total shareholders’ equity	12,181	16,007
Total liabilities and shareholders’ equity	63,841	57,770
Non-Guarantors [Member]
CURRENT ASSETS:
Cash and cash equivalents	18,935	10,629
Accounts receivable, net	33,266	38,361
Intercompany receivable	4,740	7,610
Inventories	11,029	10,235
Deferred income tax assets, current portion	933	790
Prepaid expenses and other current assets	4,636	4,784
Total current assets	73,539	72,409
PROPERTY AND EQUIPMENT, Net	19,041	19,152
INVESTMENT IN SUBSIDIARIES	4	4
GOODWILL	57,047	56,167
INTANGIBLE ASSETS, Net	42,016	42,897
OTHER ASSETS	392	370
Total assets	192,039	190,999
CURRENT LIABILITIES:
Accounts payable	2,857	1,773
Intercompany payable	6,195	15,122
Accrued expenses and other current liabilities	7,942	8,829
Income taxes payable	4,008	3,544
Deferred revenue, current portion	1,156	1,316
Total current liabilities	22,158	30,584
DEFERRED REVENUE	24	40
DEFERRED INCOME TAX LIABILITIES	12,107	12,364
OTHER LONG-TERM LIABILITIES	1,210	1,119
Total liabilities	35,499	44,107
SHAREHOLDERS' EQUITY
Total shareholders’ equity	156,540	146,892
Total liabilities and shareholders’ equity	192,039	190,999
Intersegment Elimination [Member]
CURRENT ASSETS:
Cash and cash equivalents	(182)	(144)
Intercompany receivable	(56,257)	(54,489)
Prepaid expenses and other current assets	(30,612)	(30,609)
Total current assets	(87,051)	(85,242)
INVESTMENT IN SUBSIDIARIES	(168,721)	(162,899)
OTHER ASSETS	(7,710)	(5,450)
Total assets	(263,482)	(253,591)
CURRENT LIABILITIES:
Intercompany payable	(56,257)	(54,489)
Accrued expenses and other current liabilities	(182)	(144)
Income taxes payable	(30,612)	(30,609)
Total current liabilities	(87,051)	(85,242)
DEFERRED INCOME TAX LIABILITIES	(7,710)	(5,450)
Total liabilities	(94,761)	(90,692)
SHAREHOLDERS' EQUITY
Total shareholders’ equity	(168,721)	(162,899)
Total liabilities and shareholders’ equity	(263,482)	(253,591)
Total [Member]
CURRENT ASSETS:
Cash and cash equivalents	19,520	18,578
Accounts receivable, net	65,390	66,392
Inventories	35,615	33,370
Deferred income tax assets, current portion	5,632	5,489
Prepaid expenses and other current assets	10,752	11,738
Total current assets	136,909	135,567
PROPERTY AND EQUIPMENT, Net	64,264	64,662
GOODWILL	967,218	966,338
INTANGIBLE ASSETS, Net	699,037	735,522
DEFERRED FINANCING COSTS	39,411	38,769
OTHER ASSETS	6,731	8,295
Total assets	1,913,570	1,949,153
CURRENT LIABILITIES:
Accounts payable	12,969	12,734
Accrued expenses and other current liabilities	20,425	41,356
Income taxes payable	4,124	3,654
Deferred revenue, current portion	2,389	2,606
Current portion of long term debt, net of debt discounts	25,210	3,922
Total current liabilities	65,117	64,272
LONG TERM DEBT, NET OF DEBT DISCOUNTS	992,783	986,361
DEFERRED REVENUE	320	431
DEFERRED INCOME TAX LIABILITIES	227,034	245,496
OTHER LONG-TERM LIABILITIES	12,551	15,215
Total liabilities	1,297,805	1,311,775
SHAREHOLDERS' EQUITY
Total shareholders’ equity	615,765	637,378
Total liabilities and shareholders’ equity	$ 1,913,570	$ 1,949,153