Investments and Fair Value Measurements (Classification of Securities) (Details) - USD ($) $ in Millions |
Mar. 31, 2018 |
Dec. 31, 2017 |
|---|---|---|
| Fair Value Disclosures [Abstract] | ||
| Available-for-sale | $ 21.3 | $ 21.5 |
| Held-to-maturity | 21.5 | 21.9 |
| Trading securities | 1.6 | 1.7 |
| Total | $ 44.4 | $ 45.1 |
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- Definition Amount of investment in debt and equity securities categorized neither as trading securities nor held-to-maturity securities and intended be sold or mature one year or operating cycle, if longer. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- References No definition available.
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- Definition Amount after other than temporary impairment (OTTI) accretion, of investments in debt securities classified as held-to-maturity, expected to be converted to cash, sold or exchanged within one year or the normal operating cycle. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
- Definition Amount of investments in debt and equity securities, including, but not limited to, held-to-maturity, trading and available-for-sale expected to be converted to cash, sold or exchanged within one year or the normal operating cycle, if longer. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition Amount of investments in debt and equity securities and other forms of securities that provide ownership interests classified as trading. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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