Net Loss Per Share (Details 1) - shares shares in Thousands |
3 Months Ended | 9 Months Ended | ||
|---|---|---|---|---|
Sep. 30, 2018 |
Sep. 30, 2017 |
Sep. 30, 2018 |
Sep. 30, 2017 |
|
| Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] | ||||
| Weighted-average anti-dilutive common shares | 4,992 | 4,987 | 5,014 | 3,281 |
| Employee Stock Option [Member] | ||||
| Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] | ||||
| Weighted-average anti-dilutive common shares | 3,531 | 2,380 | 3,396 | 2,340 |
| Warrants [Member] | ||||
| Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] | ||||
| Weighted-average anti-dilutive common shares | 1,461 | 2,607 | 1,618 | 941 |