Goodwill and Intangible Assets - Intangible Assets (Detail) (USD $) In Thousands, unless otherwise specified	6 Months Ended	12 Months Ended
	Nov. 30, 2013	May 31, 2013
Schedule Of Intangible Assets [Line Items]
Gross carrying value	$ 282,736	$ 276,737
Accumulated amortization	(70,541)	(61,889)
Net carrying value	212,195	214,848
Product Technologies [Member]
Schedule Of Intangible Assets [Line Items]
Gross carrying value	149,111	150,181
Accumulated amortization	(28,623)	(24,835)
Net carrying value	120,488	125,346
Weighted avg useful life	10 years 3 months 18 days	10 years 7 months 6 days
Customer Relationships [Member]
Schedule Of Intangible Assets [Line Items]
Gross carrying value	86,640	84,479
Accumulated amortization	(34,593)	(30,595)
Net carrying value	52,047	53,884
Weighted avg useful life	11 years 10 months 24 days	14 years 9 months 18 days
Licenses [Member]
Schedule Of Intangible Assets [Line Items]
Gross carrying value	7,540	6,302
Accumulated amortization	(4,949)	(4,501)
Net carrying value	2,591	1,801
Weighted avg useful life	7 years 6 months	9 years
Trademarks [Member]
Schedule Of Intangible Assets [Line Items]
Gross carrying value	6,345	6,275
Accumulated amortization	(1,476)	(1,058)
Net carrying value	4,869	5,217
Weighted avg useful life	8 years	9 years 10 months 24 days
Distributor Relationships [Member]
Schedule Of Intangible Assets [Line Items]
Gross carrying value	900	900
Accumulated amortization	(900)	(900)
Net carrying value
Weighted avg useful life	3 years	3 years
Trademark-NAMIC [Member]
Schedule Of Intangible Assets [Line Items]
Gross carrying value	28,600	28,600
Accumulated amortization
Net carrying value	28,600	28,600
In-Process Research and Development [Member]
Schedule Of Intangible Assets [Line Items]
Gross carrying value	3,600
Accumulated amortization
Net carrying value	$ 3,600