Basis of Presentation and Summary of Significant Accounting Policies - Fair Value Valuation Assumptions (Details) |
3 Months Ended | 9 Months Ended | |
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Sep. 30, 2017 |
Sep. 30, 2018 |
Sep. 30, 2017 |
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| Organization, Consolidation and Presentation of Financial Statements [Abstract] | |||
| Risk-free interest rate (as a percent) | 2.00% | 2.80% | 2.10% |
| Expected volatility (as a percent) | 47.00% | 34.00% | 47.00% |
| Expected term | 6 years 6 months | 5 years 8 months 12 days | 6 years 9 months 18 days |
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- References No definition available.
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- Definition The estimated measure of the percentage by which a share price is expected to fluctuate during a period. Volatility also may be defined as a probability-weighted measure of the dispersion of returns about the mean. The volatility of a share price is the standard deviation of the continuously compounded rates of return on the share over a specified period. That is the same as the standard deviation of the differences in the natural logarithms of the stock prices plus dividends, if any, over the period. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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- Definition The risk-free interest rate assumption that is used in valuing an option on its own shares. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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- Definition Expected term of share-based compensation awards, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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