v2.3.0.11

Segment Information (Details) (USD $) In Thousands	3 Months Ended
	Aug. 31, 2011		Aug. 31, 2010		May 31, 2011
Net sales to external customers	$ 45,697		$ 42,923
Operating income (reduction)	9,350		9,596
Total assets	227,622		190,714		219,662
Animal Safety [Member]
Net sales to external customers	22,415		20,671
Operating income (reduction)	2,743		3,111
Total assets	98,231		85,653
Food Safety [Member]
Net sales to external customers	23,282		22,252
Operating income (reduction)	7,163		6,973
Total assets	68,689		76,781
Corporate And Eliminations [Member]
Net sales to external customers	0	[1]	0	[1]
Operating income (reduction)	(556)	[1]	(488)	[1]
Total assets	$ 60,702	[1]	$ 28,280	[1]
[1] Includes corporate assets, consisting principally of cash and cash equivalents, marketable securities, deferred assets and overhead expenses not allocated to specific business segments. Also includes the elimination of intersegment transactions.

X

- Definition

Sum of the carrying amounts as of the balance sheet date of all assets that are recognized. Assets are probable future economic benefits obtained or controlled by an entity as a result of past transactions or events.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Article 7
-Section 03
-Paragraph 12

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Topic 210
-SubTopic 10
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682
-Section S99
-Name Accounting Standards Codification
-Publisher FASB
-Paragraph 1

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Concepts (CON)
-Number 6
-Paragraph 25
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 02
-Paragraph 18
-Article 5

Reference 5: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.18)
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

Name:	us-gaap_Assets
Namespace Prefix:	us-gaap
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

X

- Definition

The net result for the period of deducting operating expenses from operating revenues.

+ Details

Name:	us-gaap_OperatingIncomeLoss
Namespace Prefix:	us-gaap
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

X

- Definition

Total revenue from sale of goods and services rendered during the reporting period, in the normal course of business, reduced by sales returns and allowances, and sales discounts.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Article 5
-Section 03
-Paragraph 1

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 225
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.1)
-URI http://asc.fasb.org/extlink&oid=6880815&loc=d3e20235-122688

+ Details

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Namespace Prefix:	us-gaap
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration