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Financial Instruments (Details Textual) | 3 Months Ended | 12 Months Ended
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Mar. 31, 2017 | Dec. 31, 2016
Investments, Debt and Equity Securities [Abstract] |  |
Average maturity of marketable securities, months | 17 months | 12 months

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- Definition Average remaining time to maturity of marketable debt securities, available-for-sale securities. + References No definition available. + Details
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- References No definition available. + Details
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