Intangible Assets - Indefinite Life Intangible Assets (Details) - USD ($) |
3 Months Ended | |
|---|---|---|
Mar. 31, 2018 |
Mar. 31, 2017 |
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| Goodwill and Intangible Assets Disclosure [Abstract] | ||
| Impairment of intangible assets, indefinite-lived (excluding goodwill) | $ 0 | $ 0 |
| X | ||||||||||
- References No definition available.
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| X | ||||||||||
- Definition Amount of impairment loss resulting from write-down of assets, excluding financial assets and goodwill, lacking physical substance and having a projected indefinite period of benefit to fair value. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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