Capital Stock - Summary of Non-Vested Stock Option Activity and Related Information (Detail) - $ / shares |
12 Months Ended | ||
|---|---|---|---|
Dec. 31, 2016 |
Dec. 31, 2015 |
Dec. 31, 2014 |
|
| Options | |||
| Outstanding non-vested stock options - beginning of year (in shares) | 132,689 | 110,829 | 0 |
| Granted (in shares) | 216,043 | 58,434 | 110,829 |
| Vested (in shares) | (56,421) | (36,574) | 0 |
| Outstanding non-vested stock options - end of year (in shares) | 292,311 | 132,689 | 110,829 |
| Weighted-Average Grant Date Fair Value ($) | |||
| Outstanding non-vested stock options - beginning of year (in dollars per share) | $ 4.75 | $ 4.25 | $ 0.00 |
| Granted (in dollars per share) | 3.74 | 5.39 | 4.25 |
| Vested (in dollars per share) | 4.64 | 4.25 | 0.00 |
| Outstanding non-vested stock options - end of year (in dollars per share) | $ 4.02 | $ 4.75 | $ 4.25 |