Business Segment Information - Reconciles of Segment Gross Profit to Income (Details) - USD ($) $ in Millions	12 Months Ended
May 31, 2020	May 31, 2019	May 31, 2018
Reconciles segment gross profit to income from continuing operations before provision for income taxes
Segment gross profit	$ 269.2	$ 329.8	$ 294.1
Provision for doubtful accounts	(5.4)	(15.8)	(0.5)
Selling, general and administrative	(220.6)	(215.4)	(208.1)
Earnings (Loss) from joint ventures	(1.9)	(0.3)	0.5
Other expenses	(2.1)	(0.8)	(0.9)
Interest expense	(9.3)	(9.5)	(8.0)
Interest income	0.5	1.0	0.1
Income from continuing operations before provision for income taxes	$ 30.4	$ 89.0	$ 77.2

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

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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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Amount of income (loss) for proportionate share of equity method investee's income (loss).

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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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Amount of expense classified as other.

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Amount of expense (reversal of expense) for expected credit loss on accounts receivable.

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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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