Note 8 - Intangible Assets (Details) - USD ($) $ in Thousands	6 Months Ended
Nov. 30, 2015	May. 31, 2015
Customer Relationships [Member]
Weighted Average Life	19 years
Cost	$ 460,945	$ 462,534
Accumulated Amortization	(97,314)	(86,052)
Net	$ 363,631	376,482
Technology-Based Intangible Assets [Member]
Weighted Average Life	11 years
Cost	$ 315,004	314,850
Accumulated Amortization	(113,744)	(99,565)
Net	$ 201,260	215,285
Trade Names [Member]
Weighted Average Life	15 years
Cost	$ 40,000	40,000
Accumulated Amortization	(11,421)	(10,088)
Net	$ 28,579	29,912
Off-Market Favorable Lease [Member]
Weighted Average Life	7 years
Cost	$ 1,200	1,200
Accumulated Amortization	(594)	(557)
Net	$ 606	643
Other Intangible Assets [Member]
Weighted Average Life	4 years
Cost	$ 428	428
Accumulated Amortization	(209)	(156)
Net	219	272
In Process Research and Development [Member]
Cost	27,700	27,700
Cost	817,577	819,012
Accumulated Amortization	(223,282)	(196,418)
Net	594,295	622,594
Cost	27,700	27,700
Cost	845,277	846,712
Net	$ 621,995	$ 650,294

Weighted average amortization period of finite-lived intangible assets acquired either individually or as part of a group of assets, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 30
-Section 50
-Paragraph 1
-Subparagraph (a)(3)
-URI http://asc.fasb.org/extlink&oid=26713463&loc=d3e16265-109275

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Accumulated amount of amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 30
-Section 50
-Paragraph 2
-Subparagraph (a)(1)
-URI http://asc.fasb.org/extlink&oid=26713463&loc=d3e16323-109275

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+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 30
-Section 50
-Paragraph 2
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=26713463&loc=d3e16323-109275

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+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 30
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6388964&loc=d3e16212-109274

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-Name Accounting Standards Codification
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-Section 50
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