Stockholders Equity (Deficit) - Summary of Material Factors Incorporated in Black-Scholes Model in Estimating Fair Value of Options Granted (Details) - $ / shares	12 Months Ended
Dec. 31, 2016	Dec. 31, 2015
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Risk-free interest rate, minimum	1.13%	1.36%
Risk-free interest rate, maximum	2.08%	2.22%
Expected volatility, minimum	59.90%	60.50%
Expected volatility, maximum	93.70%	75.00%
Employee Stock Purchase Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Risk-free interest rate, minimum	0.41%
Risk-free interest rate, maximum	0.48%
Expected term	6 months
Expected volatility	70.00%
Minimum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected term	4 years 9 months 18 days	5 years
Minimum \| Common Stock
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Fair value of common stock	$ 1.98	$ 4.88
Minimum \| Common Stock \| Employee Stock Purchase Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Fair value of common stock	$ 3.03
Maximum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected term	6 years 2 months 12 days	10 years
Maximum \| Common Stock
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Fair value of common stock	$ 2.88	$ 14.64
Maximum \| Common Stock \| Employee Stock Purchase Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Fair value of common stock	$ 4.09

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.

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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.

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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.

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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.

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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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- 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.

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- Definition

Price of a single share of a number of saleable stocks of a company.

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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.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (f)(2)(i)
-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-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=27013229&loc=d3e301413-122809

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