Basis of Presentation, Business Description and Summary of Significant Accounting Policies (Details) (Recurring [Member], USD $) In Thousands, unless otherwise specified	May 31, 2014	May 31, 2013
Financial Assets
Cash equivalents	$ 445	$ 114
Marketable securities	1,809us-gaap_AvailableForSaleSecurities	2,153us-gaap_AvailableForSaleSecurities
Total Financial Assets	2,254us-gaap_AssetsFairValueDisclosure	2,267us-gaap_AssetsFairValueDisclosure
Financial Liabilities
Total Financial Liabilities	67,886us-gaap_LiabilitiesFairValueDisclosure	75,571us-gaap_LiabilitiesFairValueDisclosure
Interest rate swap agreements [Member]
Financial Liabilities
Total Financial Liabilities	555	522
Contingent liability for acquisition earn out [Member]
Financial Liabilities
Total Financial Liabilities	67,331	75,049
Corporate bond securities [Member]
Financial Assets
Marketable securities		303
U.S. government agency obligations [Member]
Financial Assets
Marketable securities	1,809	1,850
Money market funds [Member]
Financial Assets
Cash equivalents	445	114
Level 1 [Member]
Financial Assets
Cash equivalents	445	114
Marketable securities	0	0
Total Financial Assets	445	114
Financial Liabilities
Total Financial Liabilities	0	0
Level 1 [Member] \| Interest rate swap agreements [Member]
Financial Liabilities
Total Financial Liabilities	0	0
Level 1 [Member] \| Contingent liability for acquisition earn out [Member]
Financial Liabilities
Total Financial Liabilities	0	0
Level 1 [Member] \| Corporate bond securities [Member]
Financial Assets
Marketable securities		0
Level 1 [Member] \| U.S. government agency obligations [Member]
Financial Assets
Marketable securities	0	0
Level 1 [Member] \| Money market funds [Member]
Financial Assets
Cash equivalents	445	114
Level 2 [Member]
Financial Assets
Cash equivalents	0	0
Marketable securities	0	303
Total Financial Assets	0	303
Financial Liabilities
Total Financial Liabilities	555	522
Level 2 [Member] \| Interest rate swap agreements [Member]
Financial Liabilities
Total Financial Liabilities	555	522
Level 2 [Member] \| Contingent liability for acquisition earn out [Member]
Financial Liabilities
Total Financial Liabilities	0	0
Level 2 [Member] \| Corporate bond securities [Member]
Financial Assets
Marketable securities		303
Level 2 [Member] \| U.S. government agency obligations [Member]
Financial Assets
Marketable securities	0	0
Level 2 [Member] \| Money market funds [Member]
Financial Assets
Cash equivalents	0	0
Level 3 [Member]
Financial Assets
Cash equivalents	0	0
Marketable securities	1,809	1,850
Total Financial Assets	1,809	1,850
Financial Liabilities
Total Financial Liabilities	67,331	75,049
Level 3 [Member] \| Interest rate swap agreements [Member]
Financial Liabilities
Total Financial Liabilities	0	0
Level 3 [Member] \| Contingent liability for acquisition earn out [Member]
Financial Liabilities
Total Financial Liabilities	67,331	75,049
Level 3 [Member] \| Corporate bond securities [Member]
Financial Assets
Marketable securities		0
Level 3 [Member] \| U.S. government agency obligations [Member]
Financial Assets
Marketable securities	1,809	1,850
Level 3 [Member] \| Money market funds [Member]
Financial Assets
Cash equivalents	$ 0	$ 0

Fair value portion of probable future economic benefits obtained or controlled by an entity as a result of past transactions or events.

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-Publisher FASB

-Name Accounting Standards Codification

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Amount of investment in debt and equity securities categorized neither as held-to-maturity nor trading.

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Fair value portion 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.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

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Fair value of financial and nonfinancial obligations.

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