Business Segment Information (Details 2) (USD $) In Millions, unless otherwise specified	3 Months Ended
Aug. 31, 2014	Aug. 31, 2013
Reconciliation of segment gross profit to consolidated income before provision for income taxes
Segment gross profit	$ 75.3	$ 84.7
Selling, general and administrative	(44.9)	(47.7)
Earnings from joint ventures	0.6	1.2
Interest expense	(9.6)	(11.0)
Interest income	0.1	0.3
Income before provision for income taxes	$ 21.5	$ 27.5

Sum of operating profit and nonoperating income (expense) before income taxes and noncontrolling interest.

No definition available.

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Aggregate revenue less cost of goods and services sold or operating expenses directly attributable to the revenue generation activity.

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This item represents the entity's proportionate share for the period of the net income (loss) of its investee (such as unconsolidated subsidiaries and joint ventures) to which the equity method of accounting is applied. This item includes income or expense related to stock-based compensation based on the investor's grant of stock to employees of an equity method investee.

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Amount of the cost of borrowed funds accounted for as interest expense.

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Amount before accretion (amortization) of purchase discount (premium) of interest income on nonoperating securities.

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The aggregate total costs related to selling a firm's product and services, as well as all other general and administrative expenses. Direct selling expenses (for example, credit, warranty, and advertising) are expenses that can be directly linked to the sale of specific products. Indirect selling expenses are expenses that cannot be directly linked to the sale of specific products, for example telephone expenses, Internet, and postal charges. General and administrative expenses include salaries of non-sales personnel, rent, utilities, communication, etc.

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