Share-based compensation - Options (Details) - $ / shares |
3 Months Ended | 9 Months Ended | |||
|---|---|---|---|---|---|
Sep. 30, 2017 |
Sep. 30, 2016 |
Sep. 30, 2017 |
Sep. 30, 2016 |
Dec. 31, 2016 |
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| Share-based compensation | |||||
| Number of options granted (in shares) | 8,756,211 | 2,414,576 | 28,959,363 | 17,758,373 | |
| Weighted average fair value (in dollars per share) | $ 0.34 | $ 0.74 | $ 0.34 | $ 0.74 | |
| Number of options outstanding (in share) | 74,145,505 | 74,145,505 | 49,237,290 | ||
| X | ||||||||||
- References No definition available.
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- Definition Gross number of share options (or share units) granted during the period. No definition available.
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- 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
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- Definition Number of options outstanding, including both vested and non-vested options. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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