Funds Held for Clients and Corporate Investments (Realized Gains and Losses from Sale of Available-for-sale Securities) (Details) - USD ($) $ in Millions |
3 Months Ended | 12 Months Ended | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
Feb. 28, 2018 |
[1] | Aug. 31, 2016 |
[1] | May 31, 2018 |
May 31, 2017 |
May 31, 2016 |
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| Funds Held for Clients and Corporate Investments [Abstract] | |||||||||||
| Gross realized gains | $ 0.3 | $ 0.1 | $ 0.1 | ||||||||
| Gross realized losses | (0.2) | ||||||||||
| Net realized gains | $ 0.1 | $ 0.1 | $ 0.1 | [1] | $ 0.1 | [1] | $ 0.1 | ||||
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| X | ||||||||||
- Definition Funds held for clients and corporate investments. 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. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
- Definition This item represents the gross profit realized on the sale of debt or equity securities categorized neither as held-to-maturity nor trading securities. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
- Definition This item represents the gross loss realized on the sale of debt or equity securities categorized neither as held-to-maturity nor trading securities. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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