Note 17 - Condensed Consolidating Financial Information of Guarantor Subsidiaries (Details) - Condensed Consolidating Cash Flow Information - USD ($) $ in Thousands	3 Months Ended
Aug. 31, 2015	Aug. 31, 2014
Condensed Cash Flow Statements, Captions [Line Items]
Net cash provided by (used in) operating activities	$ (7,907)	$ (306)
Net cash used in investing activities	(5,841)	(3,526)
Net cash (used in) provided by financing activities	14,338	(1,664)
Effect of exchange rate changes on cash and cash equivalents	74	(770)
Increase (decrease) in cash and cash equivalents	664	(6,266)
Cash and cash equivalents at beginning of period	18,363	23,621
Cash and cash equivalents at end of period	19,027	17,355
Parent Company [Member]
Condensed Cash Flow Statements, Captions [Line Items]
Net cash provided by (used in) operating activities	(9,987)	2,858
Net cash used in investing activities	(4,942)	(2,728)
Net cash (used in) provided by financing activities	14,342	(1,659)
Effect of exchange rate changes on cash and cash equivalents	10	(57)
Increase (decrease) in cash and cash equivalents	(577)	(1,586)
Cash and cash equivalents at beginning of period	7,080	4,898
Cash and cash equivalents at end of period	6,503	3,312
Guarantor Subsidiaries [Member]
Condensed Cash Flow Statements, Captions [Line Items]
Net cash provided by (used in) operating activities	691	124
Net cash used in investing activities	(873)	(369)
Net cash (used in) provided by financing activities	(4)	(5)
Increase (decrease) in cash and cash equivalents	(186)	(250)
Cash and cash equivalents at beginning of period	(263)	(445)
Cash and cash equivalents at end of period	(449)	(695)
Non-Guarantor Subsidiaries [Member]
Condensed Cash Flow Statements, Captions [Line Items]
Net cash provided by (used in) operating activities	1,389	(3,288)
Net cash used in investing activities	(26)	(429)
Effect of exchange rate changes on cash and cash equivalents	64	(713)
Increase (decrease) in cash and cash equivalents	1,427	(4,430)
Cash and cash equivalents at beginning of period	11,546	19,168
Cash and cash equivalents at end of period	$ 12,973	$ 14,738

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)

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-Name Accounting Standards Codification

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-Name Accounting Standards Codification

-Topic 210

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Amount of increase (decrease) in cash and cash equivalents. Cash and cash equivalents are the 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. Includes effect from exchange rate changes.

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Amount of increase (decrease) from the effect of exchange rate changes on cash and cash equivalent balances held in foreign currencies.

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Amount of cash inflow (outflow) from financing activities, including discontinued operations. Financing activity cash flows include obtaining resources from owners and providing them with a return on, and a return of, their investment; borrowing money and repaying amounts borrowed, or settling the obligation; and obtaining and paying for other resources obtained from creditors on long-term credit.

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Amount of cash inflow (outflow) from investing activities, including 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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Amount of cash inflow (outflow) from operating activities, including discontinued operations. Operating activity cash flows include transactions, adjustments, and changes in value not defined as investing or financing activities.

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