Equity Incentive Plan - Summary of Stock Option Activity and Related Information (Details) - Equity Incentive Plan [Member] - $ / shares |
9 Months Ended | 12 Months Ended |
|---|---|---|
Sep. 30, 2018 |
Dec. 31, 2017 |
|
| Stock Options | ||
| Outstanding at January 1 (in shares) | 1,232,236 | |
| Granted (in shares) | 422,039 | |
| Forfeited/Expired/Exchanged (in shares) | (124,728) | |
| Outstanding at September 30 (in shares) | 1,529,547 | 1,232,236 |
| Exercisable at September 30 (in shares) | 1,397,562 | |
| Weighted Average Exercise Price | ||
| Outstanding at January 1 (in dollars per share) | $ 6.44 | |
| Granted (in dollars per share) | 1.31 | |
| Forfeited/Expired/Exchanged (in dollars per share) | 5.23 | |
| Outstanding at September 30 (in dollars per share) | 5.12 | $ 6.44 |
| Exercisable at September 30 (in dollars per share) | $ 5.22 | |
| Weighted Average Remaining Life (in years) | ||
| Outstanding (in years) | 7 years 1 month 6 days | 6 years 9 months 18 days |
| Exercisable at September 30 (in years) | 7 years |
| X | ||||||||||
- Definition Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Remaining Life [Roll Forward] No definition available.
|
| X | ||||||||||
- Definition The number of shares into which fully or partially vested stock options outstanding as of the balance sheet date can be currently converted under the option plan. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
|
| X | ||||||||||
- Definition The weighted-average price as of the balance sheet date at which grantees can acquire the shares reserved for issuance on vested portions of options outstanding and currently exercisable under the stock option plan. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
|
| X | ||||||||||
- Definition For presentations that combine terminations, the number of shares under options that were cancelled during the reporting period as a result of occurrence of a terminating event specified in contractual agreements pertaining to the stock option plan or that expired. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
|
| X | ||||||||||
- Definition Weighted average price of options that were either forfeited or expired. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
|
| X | ||||||||||
- Definition Gross number of share options (or share units) granted during the period. No definition available.
|
| X | ||||||||||
- Definition Number of options outstanding, including both vested and non-vested options. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
|
| X | ||||||||||
- Definition A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period. No definition available.
|
| X | ||||||||||
- Definition Weighted average price at which grantees can acquire the shares reserved for issuance under the stock option plan. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
|
| X | ||||||||||
- References No definition available.
|
| X | ||||||||||
- Definition Weighted average per share amount at which grantees can acquire shares of common stock by exercise of options. No definition available.
|
| X | ||||||||||
- Definition Weighted average remaining contractual term for vested portions of options outstanding and currently exercisable or convertible, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
|
| X | ||||||||||
- Definition Weighted average remaining contractual term for option awards outstanding, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
|
| X | ||||||||||
- Details
|