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.

+ References

+ Details

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- Definition

The estimated measure of the maximum 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.

+ References

No definition available.

+ Details

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- Definition

The estimated measure of the minimum 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.

+ References

No definition available.

+ Details

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- Definition

The risk-free interest rate assumption that is used in valuing an option on its own shares.

+ References

+ Details

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- Definition

The maximum risk-free interest rate assumption that is used in valuing an option on its own shares.

+ References

No definition available.

+ Details

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- Definition

The minimum risk-free interest rate assumption that is used in valuing an option on its own shares.

+ References

No definition available.

+ Details

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- Definition

Expected term of award under share-based payment arrangement, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (f)(2)(i)
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-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SAB Topic 14.D.2)
-URI http://asc.fasb.org/extlink&oid=115993241&loc=d3e301413-122809

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Stock-Based Compensation - Assumptions (Details)	12 Months Ended
Stock-Based Compensation - Assumptions (Details)	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Employee stock options
Weighted-Average Assumptions
Risk-free interest rate, min (as percent)			1.50%
Risk-free interest rate, max (as percent)			2.20%
Expected volatility, min (as percent)			23.70%
Expected volatility, max (as percent)			43.80%
Employee stock options \| Minimum
Weighted-Average Assumptions
Expected term (in years)			2 months 12 days
Employee stock options \| Maximum
Weighted-Average Assumptions
Expected term (in years)			6 years 1 month 6 days
Employee Stock Purchase Plan
Weighted-Average Assumptions
Expected term (in years)	6 months	6 months	6 months
Risk-free interest rate, min (as percent)	1.90%	1.80%
Risk-free interest rate, max (as percent)	2.60%	2.40%
Risk-free interest rate (as percent)			1.20%
Expected volatility, min (as percent)	35.00%	22.20%
Expected volatility, max (as percent)	49.00%	36.40%
Expected volatility (as percent)			28.50%