Note 17 - Condensed Consolidating Cash Flow Information (Details) - USD ($) $ in Thousands	6 Months Ended
Nov. 30, 2015	Nov. 30, 2014
Parent Company [Member]
Net cash provided by (used in) operating activities	$ 8,826	$ 12,001
Net cash used in investing activities	(6,260)	(9,770)
Net cash used in financing activities	(3,317)	(3,317)
Effect of exchange rate changes on cash and cash equivalents	267	(137)
Increase (Decrease) in cash and cash equivalents	(484)	(1,223)
Cash and cash equivalents at beginning of period	7,080	4,898
Cash and cash equivalents at end of period	6,596	3,675
Guarantor Subsidiaries [Member]
Net cash provided by (used in) operating activities	1,101	1,805
Net cash used in investing activities	(1,197)	(1,435)
Net cash used in financing activities	$ (6)	$ (12)
Effect of exchange rate changes on cash and cash equivalents
Increase (Decrease) in cash and cash equivalents	$ (102)	$ 358
Cash and cash equivalents at beginning of period	(263)	(445)
Cash and cash equivalents at end of period	(365)	(87)
Non-Guarantor Subsidiaries [Member]
Net cash provided by (used in) operating activities	(1,886)	1,603
Net cash used in investing activities	$ (282)	(7,394)
Net cash used in financing activities		(323)
Effect of exchange rate changes on cash and cash equivalents	$ (542)	(1,537)
Increase (Decrease) in cash and cash equivalents	(2,710)	(7,651)
Cash and cash equivalents at beginning of period	11,546	19,168
Cash and cash equivalents at end of period	$ 8,836	11,517
Consolidation, Eliminations [Member]
Net cash provided by (used in) operating activities		$ (396)
Net cash used in investing activities
Net cash used in financing activities		$ 324
Effect of exchange rate changes on cash and cash equivalents		$ 72
Increase (Decrease) in cash and cash equivalents
Cash and cash equivalents at beginning of period
Cash and cash equivalents at end of period
Net cash provided by (used in) operating activities	$ 8,041	$ 15,013
Net cash used in investing activities	(7,739)	(18,599)
Net cash used in financing activities	(3,323)	(3,328)
Effect of exchange rate changes on cash and cash equivalents	(275)	(1,602)
Increase (Decrease) in cash and cash equivalents	(3,296)	(8,516)
Cash and cash equivalents at beginning of period	18,363	23,621
Cash and cash equivalents at end of period	$ 15,067	$ 15,105

Amount of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates. Excludes cash and cash equivalents within disposal group and discontinued operation.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Cash
-URI http://asc.fasb.org/extlink&oid=6506951

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section 45
-Paragraph 1
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=28358313&loc=d3e6676-107765

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-Name Accounting Standards Codification
-Topic 230
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Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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-URI http://asc.fasb.org/extlink&oid=6507016

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-Name Accounting Standards Codification
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Amount of cash inflow (outflow) of investing activities, excluding discontinued operations. Investing activity cash flows include making and collecting loans and acquiring and disposing of debt or equity instruments and property, plant, and equipment and other productive assets.

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