Fair Value Measurements (Narrative) (Details) - USD ($) $ in Millions |
3 Months Ended | |
|---|---|---|
Aug. 31, 2019 |
Aug. 31, 2018 |
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| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ||
| Realized gains on available-for-sale securities | $ 0.9 | $ 0.1 |
| Maximum [Member] | ||
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ||
| Short-term investments considered cash equivalents, maturity at acquisition | 90 days | |
| X | ||||||||||
- Definition Short-term investments considered cash equivalents, maturity at acquisition No definition available.
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| X | ||||||||||
- Definition This item represents the difference between the gross realized gains and losses realized on the sale of debt or equity securities categorized neither as held-to-maturity nor trading securities. Additionally, this item would include any losses recognized for other than temporary impairments (OTTI) of the subject investments in debt and equity securities. No definition available.
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| X | ||||||||||
- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. No definition available.
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| X | ||||||||||
- Details
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