Summary of Stock Options Activity (Parenthetical) (Detail) - shares |
3 Months Ended | 9 Months Ended |
|---|---|---|
Mar. 31, 2015 |
Sep. 30, 2016 |
|
| Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | ||
| Number of Options, Granted | 1,829,537 | |
| Performance Shares | Executive Officer [Member] | ||
| Share Based Compensation Arrangement By Share Based Payment Award [Line Items] | ||
| Number of Options, Granted | 42,500 |