Note 18 - Consolidating Statements of Operations (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Feb. 29, 2016	Feb. 28, 2015	Feb. 29, 2016	Feb. 28, 2015
Parent Company [Member]
NET SALES	$ 57,913	$ 63,013	$ 185,196	$ 190,662
COST OF SALES (exclusive of amortization shown separately below)	20,150	18,743	62,491	59,702
GROSS PROFIT	37,763	44,270	122,705	130,960
Research and development	2,970	3,087	8,919	8,484
Selling and marketing	5,745	5,973	18,820	18,807
Distribution	2,288	2,772	7,224	8,167
General and administrative	8,588	6,056	22,683	20,345
Amortization expense	11,972	11,973	35,916	35,915
Total operating expenses	31,563	29,861	93,562	91,718
INCOME (LOSS) FROM OPERATIONS	6,200	14,409	29,143	39,242
Interest income	105	23	183	41
Interest expense	(22,253)	(21,664)	(66,997)	(66,553)
Other, net	4,086	173	5,046	587
Total non-operating expense	(18,062)	(21,468)	(61,768)	(65,925)
(LOSS) INCOME BEFORE INCOME TAXES	(11,862)	(7,059)	(32,625)	(26,683)
(BENEFIT) PROVISION FOR INCOME TAXES	(7,727)	31,448	(11,612)	25,044
NET (LOSS) INCOME BEFORE EARNINGS OF CONSOLIDATED SUBSIDIARIES	(4,135)	(38,507)	(21,013)	(51,727)
Net Income (Loss) of consolidated subsidiaries	(4,288)	(933)	(6,423)	(2,270)
NET (LOSS) INCOME	$ (8,423)	(39,440)	$ (27,436)	(53,997)
Net loss attributable to noncontrolling interest
NET LOSS ATTRIBUTABLE TO IMMUCOR, INC.	$ (8,423)		$ (27,436)
Net Income (Loss) of consolidated subsidiaries	(4,288)	(933)	(6,423)	(2,270)
OPERATING EXPENSES:
Research and development	2,970	3,087	8,919	8,484
Selling and marketing	5,745	5,973	18,820	18,807
Distribution	2,288	2,772	7,224	8,167
General and administrative	8,588	6,056	22,683	20,345
Amortization expense	11,972	11,973	35,916	35,915
Total operating expenses	31,563	29,861	93,562	91,718
INCOME (LOSS) FROM OPERATIONS	6,200	14,409	29,143	39,242
NON-OPERATING (EXPENSE) INCOME:
Interest income	105	23	183	41
Interest expense	(22,253)	(21,664)	(66,997)	(66,553)
Other, net	4,086	173	5,046	587
Total non-operating expense	(18,062)	(21,468)	(61,768)	(65,925)
(LOSS) INCOME BEFORE INCOME TAXES	(11,862)	(7,059)	(32,625)	(26,683)
(BENEFIT) PROVISION FOR INCOME TAXES	(7,727)	31,448	(11,612)	25,044
NET (LOSS) INCOME BEFORE EARNINGS OF CONSOLIDATED SUBSIDIARIES	(4,135)	(38,507)	(21,013)	(51,727)
Net Income (Loss) of consolidated subsidiaries	(4,288)	(933)	(6,423)	(2,270)
NET (LOSS) INCOME	$ (8,423)	(39,440)	$ (27,436)	(53,997)
Net loss attributable to noncontrolling interest
NET LOSS ATTRIBUTABLE TO IMMUCOR, INC.	$ (8,423)		$ (27,436)
NET SALES	57,913	63,013	185,196	190,662
COST OF SALES (exclusive of amortization shown separately below)	20,150	18,743	62,491	59,702
GROSS PROFIT	37,763	44,270	122,705	130,960
Guarantor Subsidiaries [Member]
NET SALES	14,370	14,119	43,423	42,175
COST OF SALES (exclusive of amortization shown separately below)	8,527	9,410	26,605	27,403
GROSS PROFIT	5,843	4,709	16,818	14,772
Research and development	3,785	4,019	11,088	12,385
Selling and marketing	2,242	2,431	7,745	7,624
Distribution	333	450	1,056	1,239
General and administrative	1,289	963	4,117	3,231
Amortization expense	1,082	1,079	3,238	3,232
Total operating expenses	8,731	8,942	27,244	27,711
INCOME (LOSS) FROM OPERATIONS	$ (2,888)	$ (4,233)	$ (10,426)	$ (12,939)
Interest income
Interest expense	$ (118)	$ (136)	$ (350)	$ (383)
Other, net	92	(349)	(154)	(436)
Total non-operating expense	(26)	(485)	(504)	(819)
(LOSS) INCOME BEFORE INCOME TAXES	(2,914)	(4,718)	(10,930)	(13,758)
(BENEFIT) PROVISION FOR INCOME TAXES	(1,045)	(1,560)	(3,833)	(5,035)
NET (LOSS) INCOME BEFORE EARNINGS OF CONSOLIDATED SUBSIDIARIES	$ (1,869)	$ (3,158)	$ (7,097)	$ (8,723)
Net Income (Loss) of consolidated subsidiaries
NET (LOSS) INCOME	$ (1,869)	$ (3,158)	$ (7,097)	$ (8,723)
Net loss attributable to noncontrolling interest
NET LOSS ATTRIBUTABLE TO IMMUCOR, INC.	$ (1,869)		$ (7,097)
Net Income (Loss) of consolidated subsidiaries
OPERATING EXPENSES:
Research and development	$ 3,785	$ 4,019	$ 11,088	$ 12,385
Selling and marketing	2,242	2,431	7,745	7,624
Distribution	333	450	1,056	1,239
General and administrative	1,289	963	4,117	3,231
Amortization expense	1,082	1,079	3,238	3,232
Total operating expenses	8,731	8,942	27,244	27,711
INCOME (LOSS) FROM OPERATIONS	$ (2,888)	$ (4,233)	$ (10,426)	$ (12,939)
NON-OPERATING (EXPENSE) INCOME:
Interest income
Interest expense	$ (118)	$ (136)	$ (350)	$ (383)
Other, net	92	(349)	(154)	(436)
Total non-operating expense	(26)	(485)	(504)	(819)
(LOSS) INCOME BEFORE INCOME TAXES	(2,914)	(4,718)	(10,930)	(13,758)
(BENEFIT) PROVISION FOR INCOME TAXES	(1,045)	(1,560)	(3,833)	(5,035)
NET (LOSS) INCOME BEFORE EARNINGS OF CONSOLIDATED SUBSIDIARIES	$ (1,869)	$ (3,158)	$ (7,097)	$ (8,723)
Net Income (Loss) of consolidated subsidiaries
NET (LOSS) INCOME	$ (1,869)	$ (3,158)	$ (7,097)	$ (8,723)
Net loss attributable to noncontrolling interest
NET LOSS ATTRIBUTABLE TO IMMUCOR, INC.	$ (1,869)		$ (7,097)
NET SALES	14,370	14,119	43,423	42,175
COST OF SALES (exclusive of amortization shown separately below)	8,527	9,410	26,605	27,403
GROSS PROFIT	5,843	4,709	16,818	14,772
Non-Guarantor Subsidiaries [Member]
NET SALES	32,288	37,015	102,718	116,637
COST OF SALES (exclusive of amortization shown separately below)	21,132	24,360	67,047	74,617
GROSS PROFIT	11,156	12,655	35,671	42,020
Research and development	408	174	746	605
Selling and marketing	5,264	5,109	15,492	17,511
Distribution	1,534	1,764	4,689	5,936
General and administrative	1,929	2,343	6,360	7,367
Amortization expense	521	563	1,591	1,801
Total operating expenses	9,656	9,953	28,878	33,220
INCOME (LOSS) FROM OPERATIONS	1,500	2,702	6,793	8,800
Interest income	54	44	114	167
Interest expense	(69)	(18)	(93)	(54)
Other, net	(4,215)	353	(4,978)	314
Total non-operating expense	(4,230)	379	(4,957)	427
(LOSS) INCOME BEFORE INCOME TAXES	(2,730)	3,081	1,836	9,227
(BENEFIT) PROVISION FOR INCOME TAXES	(73)	856	1,399	2,774
NET (LOSS) INCOME BEFORE EARNINGS OF CONSOLIDATED SUBSIDIARIES	$ (2,657)	$ 2,225	$ 437	$ 6,453
Net Income (Loss) of consolidated subsidiaries
NET (LOSS) INCOME	$ (2,657)	$ 2,225	$ 437	$ 6,453
Net loss attributable to noncontrolling interest	(237)		(237)
NET LOSS ATTRIBUTABLE TO IMMUCOR, INC.	$ (2,420)		$ 674
Net Income (Loss) of consolidated subsidiaries
OPERATING EXPENSES:
Research and development	$ 408	$ 174	$ 746	$ 605
Selling and marketing	5,264	5,109	15,492	17,511
Distribution	1,534	1,764	4,689	5,936
General and administrative	1,929	2,343	6,360	7,367
Amortization expense	521	563	1,591	1,801
Total operating expenses	9,656	9,953	28,878	33,220
INCOME (LOSS) FROM OPERATIONS	1,500	2,702	6,793	8,800
NON-OPERATING (EXPENSE) INCOME:
Interest income	54	44	114	167
Interest expense	(69)	(18)	(93)	(54)
Other, net	(4,215)	353	(4,978)	314
Total non-operating expense	(4,230)	379	(4,957)	427
(LOSS) INCOME BEFORE INCOME TAXES	(2,730)	3,081	1,836	9,227
(BENEFIT) PROVISION FOR INCOME TAXES	(73)	856	1,399	2,774
NET (LOSS) INCOME BEFORE EARNINGS OF CONSOLIDATED SUBSIDIARIES	$ (2,657)	$ 2,225	$ 437	$ 6,453
Net Income (Loss) of consolidated subsidiaries
NET (LOSS) INCOME	$ (2,657)	$ 2,225	$ 437	$ 6,453
Net loss attributable to noncontrolling interest	(237)		(237)
NET LOSS ATTRIBUTABLE TO IMMUCOR, INC.	(2,420)		674
NET SALES	32,288	37,015	102,718	116,637
COST OF SALES (exclusive of amortization shown separately below)	21,132	24,360	67,047	74,617
GROSS PROFIT	11,156	12,655	35,671	42,020
Consolidation, Eliminations [Member]
NET SALES	(15,678)	(18,542)	(49,483)	(55,151)
COST OF SALES (exclusive of amortization shown separately below)	(15,679)	$ (18,542)	$ (49,483)	$ (55,151)
GROSS PROFIT	1
Research and development	$ (253)		$ (253)
Selling and marketing
Distribution
General and administrative	$ (27)		$ (27)
Amortization expense
Total operating expenses	$ (280)		$ (280)
INCOME (LOSS) FROM OPERATIONS	281		280
Interest income	(111)	$ (25)	(165)	$ (77)
Interest expense	111	$ 25	165	$ 77
Other, net	(280)		(280)
Total non-operating expense	(280)		$ (280)
(LOSS) INCOME BEFORE INCOME TAXES	$ 1
(BENEFIT) PROVISION FOR INCOME TAXES
NET (LOSS) INCOME BEFORE EARNINGS OF CONSOLIDATED SUBSIDIARIES	$ 1
Net Income (Loss) of consolidated subsidiaries	4,288	$ 933	$ 6,423	$ 2,270
NET (LOSS) INCOME	$ 4,289	933	$ 6,423	2,270
Net loss attributable to noncontrolling interest
NET LOSS ATTRIBUTABLE TO IMMUCOR, INC.	$ 4,289		$ 6,423
Net Income (Loss) of consolidated subsidiaries	4,288	$ 933	6,423	$ 2,270
OPERATING EXPENSES:
Research and development	$ (253)		$ (253)
Selling and marketing
Distribution
General and administrative	$ (27)		$ (27)
Amortization expense
Total operating expenses	$ (280)		$ (280)
INCOME (LOSS) FROM OPERATIONS	281		280
NON-OPERATING (EXPENSE) INCOME:
Interest income	(111)	$ (25)	(165)	$ (77)
Interest expense	111	$ 25	165	$ 77
Other, net	(280)		(280)
Total non-operating expense	(280)		$ (280)
(LOSS) INCOME BEFORE INCOME TAXES	$ 1
(BENEFIT) PROVISION FOR INCOME TAXES
NET (LOSS) INCOME BEFORE EARNINGS OF CONSOLIDATED SUBSIDIARIES	$ 1
Net Income (Loss) of consolidated subsidiaries	4,288	$ 933	$ 6,423	$ 2,270
NET (LOSS) INCOME	$ 4,289	933	$ 6,423	2,270
Net loss attributable to noncontrolling interest
NET LOSS ATTRIBUTABLE TO IMMUCOR, INC.	$ 4,289		$ 6,423
NET SALES	(15,678)	(18,542)	(49,483)	(55,151)
COST OF SALES (exclusive of amortization shown separately below)	(15,679)	$ (18,542)	$ (49,483)	$ (55,151)
GROSS PROFIT	1
NET SALES	88,893	$ 95,605	$ 281,854	$ 294,323
COST OF SALES (exclusive of amortization shown separately below)	34,130	33,971	106,660	106,571
GROSS PROFIT	54,763	61,634	175,194	187,752
Research and development	6,910	7,280	20,500	21,474
Selling and marketing	13,251	13,513	42,057	43,942
Distribution	4,155	4,986	12,969	15,342
General and administrative	11,779	9,362	33,133	30,943
Amortization expense	13,575	13,615	40,745	40,948
Total operating expenses	49,670	48,756	149,404	152,649
INCOME (LOSS) FROM OPERATIONS	5,093	12,878	25,790	35,103
Interest income	48	42	132	131
Interest expense	(22,329)	(21,793)	(67,275)	(66,913)
Other, net	(317)	177	(366)	465
Total non-operating expense	(22,598)	(21,574)	(67,509)	(66,317)
(LOSS) INCOME BEFORE INCOME TAXES	(17,505)	(8,696)	(41,719)	(31,214)
(BENEFIT) PROVISION FOR INCOME TAXES	(8,845)	30,744	(14,046)	22,783
NET (LOSS) INCOME BEFORE EARNINGS OF CONSOLIDATED SUBSIDIARIES	$ (8,660)	$ (39,440)	$ (27,673)	$ (53,997)
Net Income (Loss) of consolidated subsidiaries
NET (LOSS) INCOME	$ (8,660)	$ (39,440)	$ (27,673)	$ (53,997)
Net loss attributable to noncontrolling interest	(237)		(237)
NET LOSS ATTRIBUTABLE TO IMMUCOR, INC.	$ (8,423)	$ (39,440)	$ (27,436)	$ (53,997)
Net Income (Loss) of consolidated subsidiaries
Research and development	$ 6,910	$ 7,280	$ 20,500	$ 21,474
Selling and marketing	13,251	13,513	42,057	43,942
Distribution	4,155	4,986	12,969	15,342
General and administrative	11,779	9,362	33,133	30,943
Amortization expense	13,575	13,615	40,745	40,948
Total operating expenses	49,670	48,756	149,404	152,649
INCOME (LOSS) FROM OPERATIONS	5,093	12,878	25,790	35,103
Interest income	48	42	132	131
Interest expense	(22,329)	(21,793)	(67,275)	(66,913)
Other, net	(317)	177	(366)	465
Total non-operating expense	(22,598)	(21,574)	(67,509)	(66,317)
(LOSS) INCOME BEFORE INCOME TAXES	(17,505)	(8,696)	(41,719)	(31,214)
(BENEFIT) PROVISION FOR INCOME TAXES	(8,845)	30,744	(14,046)	22,783
NET (LOSS) INCOME BEFORE EARNINGS OF CONSOLIDATED SUBSIDIARIES	$ (8,660)	$ (39,440)	$ (27,673)	$ (53,997)
Net Income (Loss) of consolidated subsidiaries
NET (LOSS) INCOME	$ (8,660)	$ (39,440)	$ (27,673)	$ (53,997)
Net loss attributable to noncontrolling interest	(237)		(237)
NET LOSS ATTRIBUTABLE TO IMMUCOR, INC.	(8,423)	$ (39,440)	(27,436)	$ (53,997)
NET SALES	88,893	95,605	281,854	294,323
COST OF SALES (exclusive of amortization shown separately below)	34,130	33,971	106,660	106,571
GROSS PROFIT	$ 54,763	$ 61,634	$ 175,194	$ 187,752