Restructuring and Impairment Charges (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
May 31, 2012	May 31, 2011 item	May 31, 2013 Structures and Systems segment	May 31, 2012 Structures and Systems segment item
Restructuring and Impairment Charges
Number of plants which will be closed				2
Number of idle facilities which will be closed				1
Impairment charges		$ 5.3	$ 2.5
Other charges	3.7	5.3	3.7
Severance expense			1.2
Number of narrow body aircraft offered for sale		1
Net realizable value		$ 8.9

The charge against earnings resulting from the aggregate write down of all assets from their carrying value to their fair value.

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The charge against earnings in the period for known and estimated costs of termination benefits provided to current employees that are involuntarily terminated under a benefit arrangement associated with exit from or disposal of business activities or restructurings pursuant to a duly authorized plan, excluding costs or losses pertaining to an entity newly acquired in a business combination or a discontinued operation as defined by generally accepted accounting principles and costs associated with one-time termination benefits.

+ References

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-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.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.

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