Stock-Based Compensation - Assumptions (Details) - shares	3 Months Ended
Mar. 31, 2017	Mar. 31, 2016
Employee and non-employee stock options
Stock Based Compensation
Options granted (in shares)	146,000
Employee stock options
Valuation of Stock Option Grants to Employees
Expected term	5 years 1 month 6 days
Expected volatility, maximum	62.70%
Expected dividend rate	0.00%	0.00%
Risk free interest rate, maximum	1.91%
Employee stock options \| Minimum
Valuation of Stock Option Grants to Employees
Expected term		5 years 1 month 6 days
Expected volatility, minimum		70.60%
Risk free interest rate, minimum		1.25%
Employee stock options \| Maximum
Valuation of Stock Option Grants to Employees
Expected term		5 years 2 months 12 days
Expected volatility, maximum		71.00%
Risk free interest rate, maximum		1.51%
Non-employee stock options
Stock Based Compensation
Options granted (in shares)	141,046
Options unvested (in shares)	8,693
Valuation of Stock Option Grants to Employees
Expected term	2 years 8 months 12 days	3 years 2 months 12 days
Expected volatility, maximum	51.70%	72.60%
Expected dividend rate	0.00%	0.00%
Risk free interest rate, maximum	1.42%	0.90%

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 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.

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No definition available.

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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 maximum 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 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

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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No definition available.

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- Definition

Gross number of share options (or share units) granted during the period.

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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.

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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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- Definition

Number of non-vested options outstanding.

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No definition available.

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