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Stock-based compensation (Tables) | 12 Months Ended
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Dec. 31, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |
Schedule of stock-based compensation expenses included in general and administrative expenses | Stock-based compensation expenses included in general and administrative expenses are as follows:
Year ended December 31, | Note |  | 2019 |  |  | 2018 |
Restricted share unit plan | 18(a) |  | $ | 1,933 |  |  | $ | 2,110 |
Performance restricted share unit plan | 18(b) |  | 1,892 |  |  | 1,910 |
Deferred stock unit plan | 18(c) |  | 5,618 |  |  | 7,415 |
Share option plan | 18(d) |  | — |  |  | 97 |
|  |  | $ | 9,443 |  |  | $ | 11,532 |
Schedule of performance restricted share units |
|  | Number of units |  | Weighted-average exercise price $ per share |
Outstanding at December 31, 2017 |  | 896,633 |  |  | 4.81 |
Granted |  | 197,763 |  |  | 8.01 |
Vested |  | (353,279 | ) |  | 4.27 |
Outstanding at December 31, 2018 |  | 741,117 |  |  | 5.92 |
Granted |  | 122,274 |  |  | 13.12 |
Vested |  | (372,924 | ) |  | 4.45 |
Forfeited |  | (8,560 | ) |  | 8.09 |
Outstanding at December 31, 2019 |  | 481,907 |  |  | 8.85 |
Schedule of assumptions used in estimate of fair value | The Company estimated the fair value of the PSUs granted during the years ended December 31, 2019 and 2018 using a Monte Carlo simulation with the following assumptions:
|  | 2019 |  |  | 2018 |
Risk-free interest rate |  | 1.43 | % |  | 1.98 | %
Expected volatility |  | 40.12 | % |  | 45.04 | %
Schedule of stock plan activity |
|  | Number of units |
Outstanding at December 31, 2017 |  | 991,583 |
Granted |  | 134,656 |
Outstanding at December 31, 2018 |  | 1,126,239 |
Granted |  | 82,191 |
Redeemed |  | (307,385 | )
Outstanding at December 31, 2019 |  | 901,045 |
Schedule of stock options activity |
|  | Number of options |  |  | Weighted-average exercise price $ per share |
Outstanding at December 31, 2017 |  | 913,540 |  |  | 5.36 |
Exercised(i) |  | (297,940 | ) |  | 3.43 |
Forfeited or expired |  | (50,000 | ) |  | 16.46 |
Outstanding at December 31, 2018 |  | 565,600 |  |  | 5.40 |
Exercised(i) |  | (327,000 | ) |  | 5.97 |
Outstanding at December 31, 2019 |  | 238,600 |  |  | 4.61 |
(i) All stock options exercised resulted in new common shares being issued (note 15(a)).
Summary of information about stock options outstanding | The following table summarizes information about stock options outstanding at December 31, 2019:
|  | Options outstanding and exercisable |
Exercise price |  | Number |  |  | Weighted-average remaining life |  | Weighted- average exercise price |
$2.75 |  | 85,100 |  |  | 2.7 years |  | $ | 2.75 |
$2.79 |  | 50,000 |  |  | 2.5 years |  | $ | 2.79 |
$5.91 |  | 46,300 |  |  | 3.4 years |  | $ | 5.91 |
$6.56 |  | 34,000 |  |  | 1.6 years |  | $ | 6.56 |
$9.33 |  | 5,300 |  |  | 0.5 years |  | $ | 9.33 |
$10.13 |  | 17,900 |  |  | 0.8 years |  | $ | 10.13 |
|  | 238,600 |  |  | 2.4 years |  | $ | 4.61 |
Equity classified restricted share unit plan |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |
Schedule of restricted share unit plan activity |
|  | Number of units |  |  | Weighted-average exercise price $ per share |
Outstanding at December 31, 2017 |  | 1,189,933 |  |  | 4.22 |
Granted |  | 266,196 |  |  | 8.02 |
Vested |  | (487,376 | ) |  | 3.01 |
Forfeited |  | (20,660 | ) |  | 5.45 |
Outstanding at December 31, 2018 |  | 948,093 |  |  | 5.88 |
Granted |  | 193,450 |  |  | 13.40 |
Vested |  | (465,194 | ) |  | 4.15 |
Forfeited |  | (26,272 | ) |  | 6.01 |
Outstanding at December 31, 2019 |  | 650,077 |  |  | 9.35 |

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- Definition Tabular disclosure of activity for award under share-based payment arrangement. Includes, but is not limited to, outstanding award at beginning and end of year, granted, exercised, forfeited, and weighted-average grant date fair value. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (e) -URI http://asc.fasb.org/extlink&oid=116856206&loc=d3e5070-113901 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c)(2) -URI http://asc.fasb.org/extlink&oid=116856206&loc=d3e5070-113901 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (d) -URI http://asc.fasb.org/extlink&oid=116856206&loc=d3e5070-113901 + Details
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- Definition Tabular disclosure for stock option plans. Includes, but is not limited to, outstanding awards at beginning and end of year, grants, exercises, forfeitures, and weighted-average grant date fair value. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (d) -URI http://asc.fasb.org/extlink&oid=116856206&loc=d3e5070-113901 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (e) -URI http://asc.fasb.org/extlink&oid=116856206&loc=d3e5070-113901 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c)(1) -URI http://asc.fasb.org/extlink&oid=116856206&loc=d3e5070-113901 + Details
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- Definition Tabular disclosure of the significant assumptions used during the year to estimate the fair value of stock options, including, but not limited to: (a) expected term of share options and similar instruments, (b) expected volatility of the entity's shares, (c) expected dividends, (d) risk-free rate(s), and (e) discount for post-vesting restrictions. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (f)(2) -URI http://asc.fasb.org/extlink&oid=116856206&loc=d3e5070-113901 + Details
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