Offering period under the plan.

No definition available.

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- Definition

Percentage common stock outstanding shares.

+ References

No definition available.

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- Definition

Percentage of purchase price with respect to each offering period.

+ References

No definition available.

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- Definition

Amount of expense for award under share-based payment arrangement. Excludes amount capitalized.

+ References

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- Definition

Number of common shares reserved for future issuance related to deferred compensation arrangements with individuals.

+ References

No definition available.

+ Details

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- Definition

Maximum percentage of employee gross pay the employee may contribute to a defined contribution plan.

+ References

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.

+ References

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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

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- Definition

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

+ References

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

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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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- Definition

Number of shares issued during the period as a result of an employee stock purchase plan.

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Stockholders' Equity Common Stock - 2015 Employee Stock Purchase Plan - Additional Information (Detail) - USD ($) $ in Thousands		12 Months Ended
	Jun. 16, 2015	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense		$ 8,344	$ 16,641	$ 17,362
2015 Employee Stock Purchase Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Aggregate shares of common stock reserved for issuance	365,000		1,847,474
Shares issued under ESPP	400,000	108,346
Percentage of common stock shares outstanding	1.00%
Percentage of eligible earning contributed toward semi-annual purchase of common stock		15.00%
Offering period under the plan		6 months
Percentage of purchase price with respect to each offering period		85.00%
Risk-free interest rate		1.73%
Expected term (in years)		6 months
Expected volatility		75.90%
Expected dividend yield		0.00%
Stock-based compensation expense		$ 109	$ 145	$ 0