Stock options and warrants (Schedule of Nonvested Awards) (Details) - Stock Incentive Plan [Member] - $ / shares |
9 Months Ended | |
|---|---|---|
Sep. 30, 2015 |
Sep. 30, 2014 |
|
| Nonvested Shares Underlying Options | ||
| Beginning balance | 319,652 | |
| Granted | 1,094,500 | |
| Vested | (296,445) | |
| Forfeited | (180,273) | (5,050) |
| Ending balance | 937,434 | |
| Weighted Average Exercise Price | ||
| Beginning balance | $ 2.28 | |
| Granted | 1.89 | |
| Vested | 2.03 | |
| Forfeited | 2.05 | $ 2.15 |
| Ending balance | 1.95 | |
| Weighted Average Grant Date Fair Value | ||
| Beginning balance | 1.85 | |
| Granted | 1.34 | |
| Vested | 1.56 | |
| Forfeited | 1.48 | |
| Ending balance | $ 1.42 | |
| X | ||||||||||
- Definition Weighted average exercise price of share-based payment awards that vested during the period. No definition available.
|
| X | ||||||||||
- Definition Weighted average exercise price of nonvested options outstanding. No definition available.
|
| X | ||||||||||
- Definition Gross number of share options (or share units) granted during the period. No definition available.
|
| X | ||||||||||
- Definition The weighted average grant-date fair value of options granted during the reporting period as calculated by applying the disclosed option pricing methodology. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- References No definition available.
|
| X | ||||||||||
- Definition Weighted average price at which grantees could have acquired the underlying shares with respect to stock options that were terminated. 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 Number of non-vested options outstanding. No definition available.
|
| 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 Number of non-vested options forfeited. No definition available.
|
| X | ||||||||||
- Definition Weighted average grant-date fair value of non-vested options forfeited. No definition available.
|
| X | ||||||||||
- Definition Weighted average grant-date fair value of non-vested options outstanding. No definition available.
|
| X | ||||||||||
- References No definition available.
|
| X | ||||||||||
- Definition Number of options vested. No definition available.
|
| X | ||||||||||
- Definition Weighted average grant-date fair value of options vested. No definition available.
|
| X | ||||||||||
- Details
|