Stock-Based Compensation - Schedule of Restricted Stock Awards Under the 2012 and 2013 Plans (Detail) - Restricted Stock [Member] |
12 Months Ended |
|---|---|
|
Dec. 31, 2015
$ / shares
shares
| |
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |
| Number of shares, Unvested beginning balance | shares | 8,493 |
| Vesting of restricted stock | shares | (3,303) |
| Number of shares, Unvested ending balance | shares | 5,190 |
| Weighted-average grant date fair value, Unvested beginning balance | $ / shares | $ 1.04 |
| Vesting of restricted stock | $ / shares | 1.00 |
| Weighted-average grant date fair value, Unvested ending balance | $ / shares | $ 1.07 |