Stockholders' Equity - Estimated Fair Value of Each Stock Option Award (Details) - $ / shares	9 Months Ended
Sep. 30, 2019	Sep. 30, 2018
Equity [Abstract]
Risk-free interest rate	2.51%	2.49%
Expected option life (in years)	5 years 8 months 12 days	6 years 3 months 18 days
Volatility rate	39.00%	36.00%
Dividend rate	0.00%	0.00%
Weighted-average grant date fair value of stock options granted (in USD per share)	$ 23.67	$ 18.76

No definition available.

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- Definition

The estimated dividend rate (a percentage of the share price) to be paid (expected dividends) to holders of the underlying shares over the option's term.

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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.

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No definition available.

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- Definition

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

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No definition available.

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- Definition

The weighted average grant-date fair value of options granted during the reporting period as calculated by applying the disclosed option pricing methodology.

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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.

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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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-Name Accounting Standards Codification
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-SubTopic 10
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-Subparagraph (SAB Topic 14.D.2)
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