Cash, Cash Equivalents and Investments - Narrative (Details) |
Jun. 30, 2018
security
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| Cash and Cash Equivalents [Abstract] | |
| Number of owned securities that were in an unrealized loss position | 9 |
| X | ||||||||||
- Definition Number of investment positions in available-for-sale investments in a continuous unrealized loss position for which an other-than-temporary impairment (OTTI) has not been recognized in the income statement. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
- References No definition available.
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