Share capital - Weighted average assumptions (Details) - USD ($) |
12 Months Ended | |
|---|---|---|
Dec. 31, 2018 |
Dec. 31, 2017 |
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| Share capital [Abstract] | ||
| Annualized volatility | 55.00% | 74.00% |
| Risk-free interest rate | 2.04% | 1.31% |
| Life of options in years | 4 | 6.6 |
| Estimated forfeiture rate, share options granted | 22.40% | 25.50% |
| Expected dividend as percentage, share options granted | 0.00% | 0.00% |
| Exercise price, share options granted | $ 5.29 | $ 4.12 |
| Market price on date of grant, share options granted | $ 5.29 | $ 4.12 |
| Share options granted, fair value | $ 2.89 | $ 2.79 |
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- Definition Estimated forfeiture rate, share options granted No definition available.
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- Definition Market price on date of grant, share options granted No definition available.
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- Definition Share capital [Abstract] No definition available.
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- Definition Share options granted, fair value No definition available.
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- Definition The expected volatility of the share price used to calculate the fair value of the share options granted. Expected volatility is a measure of the amount by which a price is expected to fluctuate during a period. The measure of volatility used in option pricing models is the annualised standard deviation of the continuously compounded rates of return on the share over a period of time. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition The option life of share options granted. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition The implied yield currently available on zero-coupon government issues of the country in whose currency the exercise price for share options granted is expressed, with a remaining term equal to the expected term of the option being valued (based on the option's remaining contractual life and taking into account the effects of expected early exercise). [Refer: Government [member]] Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition The exercise price of share options granted. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition The percentage of an expected dividend used to calculate the fair value of share options granted. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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