Capital Stock - Summary of Stock Option Information (Detail) - $ / shares |
12 Months Ended | ||
|---|---|---|---|
Dec. 31, 2016 |
Dec. 31, 2015 |
Dec. 31, 2014 |
|
| Options | |||
| Granted (in shares) | 216,043 | 58,434 | 110,829 |
| Equity Option [Member] | |||
| Options | |||
| Outstanding - beginning of year (in shares) | 321,609 | 263,175 | 0 |
| Granted (in shares) | 500,736 | 58,434 | 263,175 |
| Outstanding - end of year (in shares) | 822,345 | 321,609 | 263,175 |
| Exercisable - end of year (in shares) | 530,034 | 188,920 | 152,346 |
| Weighted-Average Exercise Price ($) | |||
| Outstanding - beginning of year (in dollars per share) | $ 4.39 | $ 4.16 | $ 0.00 |
| Granted (in dollars per share) | 3.74 | 5.39 | 4.16 |
| Outstanding - end of year (in dollars per share) | 3.99 | 4.39 | 4.16 |
| Exercisable - end of year (in dollars per share) | $ 3.97 | $ 4.13 | $ 4.10 |