Note 16 - Condensed Consolidating Financial Information Of Guarantor Subsidiaries (Details) - Condensed Consolidating Balance Sheets (USD $) In Thousands, unless otherwise specified	Nov. 30, 2013	May 31, 2013	Nov. 30, 2012	May 31, 2012
CURRENT ASSETS:
Cash and cash equivalents	$ 36,223	$ 29,388	$ 19,013	$ 18,578
Accounts receivable, net	70,774	68,086
Inventories	47,727	45,941
Deferred income tax assets, current portion	6,407	5,290
Prepaid expenses and other current assets	11,711	11,577
Total current assets	172,842	160,282
PROPERTY AND EQUIPMENT, net	76,234	76,381
GOODWILL	1,004,845	1,003,463		966,338
INTANGIBLE ASSETS, net	689,423	714,603
DEFERRED FINANCING COSTS	36,313	39,449
OTHER ASSETS	7,089	6,792
Total assets	1,986,746	2,000,970
CURRENT LIABILITIES:
Accounts payable	17,236	13,638
Accrued interest and interest rate swap liability	19,725	20,084
Income taxes payable	4,842	3,873
Deferred revenue, current portion	2,639	2,252
Current portion of long	4,653	6,712
Total current liabilities	68,998	73,213
LONG-TERM DEBT	1,038,875	1,039,278
DEFERRED REVENUE	123	161
DEFERRED INCOME TAX LIABILITIES	223,995	231,040
OTHER LONG-TERM LIABILITIES	13,086	12,572
Total liabilities	1,345,077	1,356,264
SHAREHOLDERS' EQUITY:
Total shareholders' equity	641,669	644,706
Total liabilities and shareholders' equity	1,986,746	2,000,970
Immucor Inc [Member]
CURRENT ASSETS:
Cash and cash equivalents	15,387	6,971
Accounts receivable, net	30,517	26,517
Intercompany receivable	56,196	54,443
Inventories	21,322	18,551
Deferred income tax assets, current portion	3,096	3,098
Prepaid expenses and other current assets	6,353	6,360
Total current assets	132,871	115,940
PROPERTY AND EQUIPMENT, net	38,888	40,124
INVESTMENT IN SUBSIDIARIES	245,215	248,150
GOODWILL	903,512	903,802
INTANGIBLE ASSETS, net	610,211	634,194
DEFERRED FINANCING COSTS	36,313	39,449
OTHER ASSETS	6,532	6,203
Total assets	1,973,542	1,987,862
CURRENT LIABILITIES:
Accounts payable	8,906	7,587
Intercompany payable	626	424
Accrued interest and interest rate swap liability	19,725
Accrued expenses and other current liabilities	6,603	31,737
Income taxes payable	31,165	30,879
Deferred revenue, current portion	1,452	1,086
Current portion of long	4,632	6,673
Total current liabilities	73,109	78,386
LONG-TERM DEBT	1,038,859	1,039,250
DEFERRED REVENUE	31	62
DEFERRED INCOME TAX LIABILITIES	208,264	214,222
OTHER LONG-TERM LIABILITIES	11,610	11,236
Total liabilities	1,331,873	1,343,156
SHAREHOLDERS' EQUITY:
Total shareholders' equity	641,669	644,706
Total liabilities and shareholders' equity	1,973,542	1,987,862
Guarantor [Member]
CURRENT ASSETS:
Cash and cash equivalents	172	4,107
Accounts receivable, net	5,022	5,552
Intercompany receivable	12,537	7,961
Inventories	15,142	15,897
Deferred income tax assets, current portion	1,943	1,097
Prepaid expenses and other current assets	477	483
Total current assets	35,293	35,097
PROPERTY AND EQUIPMENT, net	16,594	17,060
INVESTMENT IN SUBSIDIARIES	5,250	5,743
GOODWILL	42,053	41,763
INTANGIBLE ASSETS, net	38,288	39,523
OTHER ASSETS	196	184
Total assets	137,674	139,370
CURRENT LIABILITIES:
Accounts payable	4,598	3,315
Intercompany payable	63,185	59,347
Accrued expenses and other current liabilities	4,737	5,290
Income taxes payable	(30,657)	(30,457)
Deferred revenue, current portion		6
Current portion of long	21	39
Total current liabilities	41,884	37,540
LONG-TERM DEBT	16	28
DEFERRED INCOME TAX LIABILITIES	3,796	4,861
OTHER LONG-TERM LIABILITIES	122	114
Total liabilities	45,818	42,543
SHAREHOLDERS' EQUITY:
Total shareholders' equity	91,856	96,827
Total liabilities and shareholders' equity	137,674	139,370
Non-Guarantors [Member]
CURRENT ASSETS:
Cash and cash equivalents	20,664	18,310
Accounts receivable, net	35,235	36,017
Intercompany receivable	3,743	4,313
Inventories	13,210	12,978
Deferred income tax assets, current portion	616	533
Prepaid expenses and other current assets	4,881	4,734
Total current assets	78,349	76,885
PROPERTY AND EQUIPMENT, net	20,752	19,197
INVESTMENT IN SUBSIDIARIES	4	4
GOODWILL	59,280	57,898
INTANGIBLE ASSETS, net	40,924	40,886
OTHER ASSETS	361	405
Total assets	199,670	195,275
CURRENT LIABILITIES:
Accounts payable	3,732	2,736
Intercompany payable	8,665	7,440
Accrued expenses and other current liabilities	8,563	9,711
Income taxes payable	4,334	3,451
Deferred revenue, current portion	1,187	1,160
Total current liabilities	26,481	24,498
DEFERRED REVENUE	92	99
DEFERRED INCOME TAX LIABILITIES	11,935	11,957
OTHER LONG-TERM LIABILITIES	1,354	1,222
Total liabilities	39,862	37,776
SHAREHOLDERS' EQUITY:
Total shareholders' equity	159,808	157,499
Total liabilities and shareholders' equity	199,670	195,275
Eliminations [Member]
CURRENT ASSETS:
Intercompany receivable	(72,476)	(66,717)
Inventories	(1,947)	(1,485)
Deferred income tax assets, current portion	752	562
Total current assets	(73,671)	(67,640)
INVESTMENT IN SUBSIDIARIES	(250,469)	(253,897)
Total assets	(324,140)	(321,537)
CURRENT LIABILITIES:
Intercompany payable	(72,476)	(67,211)
Total current liabilities	(72,476)	(67,211)
Total liabilities	(72,476)	(67,211)
SHAREHOLDERS' EQUITY:
Total shareholders' equity	(251,664)	(254,326)
Total liabilities and shareholders' equity	(324,140)	(321,537)
Total [Member]
CURRENT ASSETS:
Cash and cash equivalents	36,223	29,388
Accounts receivable, net	70,774	68,086
Inventories	47,727	45,941
Deferred income tax assets, current portion	6,407	5,290
Prepaid expenses and other current assets	11,711	11,577
Total current assets	172,842	160,282
PROPERTY AND EQUIPMENT, net	76,234	76,381
GOODWILL	1,004,845	1,003,463
INTANGIBLE ASSETS, net	689,423	714,603
DEFERRED FINANCING COSTS	36,313	39,449
OTHER ASSETS	7,089	6,792
Total assets	1,986,746	2,000,970
CURRENT LIABILITIES:
Accounts payable	17,236	13,638
Accrued interest and interest rate swap liability	19,725
Accrued expenses and other current liabilities	19,903	46,738
Income taxes payable	4,842	3,873
Deferred revenue, current portion	2,639	2,252
Current portion of long	4,653	6,712
Total current liabilities	68,998	73,213
LONG-TERM DEBT	1,038,875	1,039,278
DEFERRED REVENUE	123	161
DEFERRED INCOME TAX LIABILITIES	223,995	231,040
OTHER LONG-TERM LIABILITIES	13,086	12,572
Total liabilities	1,345,077	1,356,264
SHAREHOLDERS' EQUITY:
Total shareholders' equity	641,669	644,706
Total liabilities and shareholders' equity	$ 1,986,746	$ 2,000,970