Note 16 - Condensed Consolidating Financial Information Of Guarantor Subsidiaries (Details) - Condensed Consolidating Balance Sheets (USD $) In Thousands, unless otherwise specified	Aug. 31, 2013	May 31, 2013	Aug. 31, 2012	May 31, 2012
CURRENT ASSETS:
Cash and cash equivalents	$ 24,002	$ 29,388	$ 18,143	$ 18,578
Accounts receivable, net	66,607	68,086
Inventories	45,970	45,941
Deferred income tax assets, current portion	6,433	5,290
Prepaid expenses and other current assets	12,004	11,577
Total current assets	155,016	160,282
PROPERTY AND EQUIPMENT, net	75,340	76,381
GOODWILL	1,003,789	1,003,463		966,338
INTANGIBLE ASSETS, net	701,867	714,603
DEFERRED FINANCING COSTS	37,893	39,449
OTHER ASSETS	6,817	6,792
Total assets	1,980,722	2,000,970
CURRENT LIABILITIES:
Accounts payable	19,183	13,638
Accrued interest and interest rate swap liability	8,917	20,084
Income taxes payable	4,162	3,873
Deferred revenue, current portion	2,534	2,252
Current portion of long	4,689	6,712
Total current liabilities	62,560	73,213
LONG	1,040,231	1,039,278
DEFERRED REVENUE	137	161
DEFERRED INCOME TAX LIABILITIES	226,455	231,040
OTHER LONG-TERM LIABILITIES	12,236	12,572
Total liabilities	1,341,619	1,356,264
SHAREHOLDERS' EQUITY:
Total shareholders' equity	639,103	644,706
Total liabilities and shareholders' equity	1,980,722	2,000,970
Immucor Inc [Member]
CURRENT ASSETS:
Cash and cash equivalents	8,134	6,971
Accounts receivable, net	26,755	26,517
Intercompany receivable	53,204	54,443
Inventories	20,088	18,551
Deferred income tax assets, current portion	3,096	3,098
Prepaid expenses and other current assets	6,706	6,360
Total current assets	117,983	115,940
PROPERTY AND EQUIPMENT, net	38,716	40,124
INVESTMENT IN SUBSIDIARIES	241,565	248,150
GOODWILL	903,512	903,802
INTANGIBLE ASSETS, net	622,194	634,194
DEFERRED FINANCING COSTS	37,893	39,449
OTHER ASSETS	6,201	6,203
Total assets	1,968,064	1,987,862
CURRENT LIABILITIES:
Accounts payable	11,812	7,587
Intercompany payable	709	424
Accrued interest and interest rate swap liability	8,917
Accrued expenses and other current liabilities	9,324	31,737
Income taxes payable	31,162	30,879
Deferred revenue, current portion	1,397	1,086
Current portion of long	4,658	6,673
Total current liabilities	67,979	78,386
LONG	1,040,208	1,039,250
DEFERRED REVENUE	43	62
DEFERRED INCOME TAX LIABILITIES	209,896	214,222
OTHER LONG-TERM LIABILITIES	10,835	11,236
Total liabilities	1,328,961	1,343,156
SHAREHOLDERS' EQUITY:
Total shareholders' equity	639,103	644,706
Total liabilities and shareholders' equity	1,968,064	1,987,862
Guarantor [Member]
CURRENT ASSETS:
Cash and cash equivalents	711	4,107
Accounts receivable, net	4,952	5,552
Intercompany receivable	10,690	7,961
Inventories	14,493	15,897
Deferred income tax assets, current portion	1,943	1,097
Prepaid expenses and other current assets	618	483
Total current assets	33,407	35,097
PROPERTY AND EQUIPMENT, net	16,455	17,060
INVESTMENT IN SUBSIDIARIES	5,250	5,743
GOODWILL	42,053	41,763
INTANGIBLE ASSETS, net	38,955	39,523
OTHER ASSETS	273	184
Total assets	136,393	139,370
CURRENT LIABILITIES:
Accounts payable	4,123	3,315
Intercompany payable	59,502	59,347
Accrued expenses and other current liabilities	5,138	5,290
Income taxes payable	(30,700)	(30,457)
Deferred revenue, current portion	38	6
Current portion of long	31	39
Total current liabilities	38,132	37,540
LONG	23	28
DEFERRED INCOME TAX LIABILITIES	4,677	4,861
OTHER LONG-TERM LIABILITIES	118	114
Total liabilities	42,950	42,543
SHAREHOLDERS' EQUITY:
Total shareholders' equity	93,443	96,827
Total liabilities and shareholders' equity	136,393	139,370
Non-Guarantors [Member]
CURRENT ASSETS:
Cash and cash equivalents	15,157	18,310
Accounts receivable, net	34,900	36,017
Intercompany receivable	3,301	4,313
Inventories	13,528	12,978
Deferred income tax assets, current portion	568	533
Prepaid expenses and other current assets	4,680	4,734
Total current assets	72,134	76,885
PROPERTY AND EQUIPMENT, net	20,169	19,197
INVESTMENT IN SUBSIDIARIES	4	4
GOODWILL	58,224	57,898
INTANGIBLE ASSETS, net	40,718	40,886
OTHER ASSETS	342	405
Total assets	191,591	195,275
CURRENT LIABILITIES:
Accounts payable	3,248	2,736
Intercompany payable	6,984	7,440
Accrued expenses and other current liabilities	8,613	9,711
Income taxes payable	3,700	3,451
Deferred revenue, current portion	1,099	1,160
Total current liabilities	23,644	24,498
DEFERRED REVENUE	94	99
DEFERRED INCOME TAX LIABILITIES	11,882	11,957
OTHER LONG-TERM LIABILITIES	1,283	1,222
Total liabilities	36,903	37,776
SHAREHOLDERS' EQUITY:
Total shareholders' equity	154,688	157,499
Total liabilities and shareholders' equity	191,591	195,275
Eliminations [Member]
CURRENT ASSETS:
Intercompany receivable	(67,195)	(66,717)
Inventories	(2,139)	(1,485)
Deferred income tax assets, current portion	826	562
Total current assets	(68,508)	(67,640)
INVESTMENT IN SUBSIDIARIES	(246,819)	(253,897)
Total assets	(315,327)	(321,537)
CURRENT LIABILITIES:
Intercompany payable	(67,195)	(67,211)
Total current liabilities	(67,195)	(67,211)
Total liabilities	(67,195)	(67,211)
SHAREHOLDERS' EQUITY:
Total shareholders' equity	(248,132)	(254,326)
Total liabilities and shareholders' equity	(315,327)	(321,537)
Total [Member]
CURRENT ASSETS:
Cash and cash equivalents	24,002	29,388
Accounts receivable, net	66,607	68,086
Inventories	45,970	45,941
Deferred income tax assets, current portion	6,433	5,290
Prepaid expenses and other current assets	12,004	11,577
Total current assets	155,016	160,282
PROPERTY AND EQUIPMENT, net	75,340	76,381
GOODWILL	1,003,789	1,003,463
INTANGIBLE ASSETS, net	701,867	714,603
DEFERRED FINANCING COSTS	37,893	39,449
OTHER ASSETS	6,817	6,792
Total assets	1,980,722	2,000,970
CURRENT LIABILITIES:
Accounts payable	19,183	13,638
Accrued interest and interest rate swap liability	8,917
Accrued expenses and other current liabilities	23,075	46,738
Income taxes payable	4,162	3,873
Deferred revenue, current portion	2,534	2,252
Current portion of long	4,689	6,712
Total current liabilities	62,560	73,213
LONG	1,040,231	1,039,278
DEFERRED REVENUE	137	161
DEFERRED INCOME TAX LIABILITIES	226,455	231,040
OTHER LONG-TERM LIABILITIES	12,236	12,572
Total liabilities	1,341,619	1,356,264
SHAREHOLDERS' EQUITY:
Total shareholders' equity	639,103	644,706
Total liabilities and shareholders' equity	$ 1,980,722	$ 2,000,970