Stock Option Plans - Additional Information (Detail)
$ / shares in Units, $ in Thousands |
|
12 Months Ended |
|
|
|
Sep. 04, 2015
$ / shares
shares
|
Dec. 31, 2015
USD ($)
Offering Period
$ / shares
shares
|
Dec. 31, 2014
USD ($)
$ / shares
shares
|
Dec. 31, 2013
USD ($)
$ / shares
shares
|
Dec. 31, 2012
shares
|
Jan. 01, 2015
shares
|
Jan. 31, 2014
shares
|
| Share Based Compensation Arrangement By Share Based Payment Award [Line Items] |
|
|
|
|
|
|
|
| Stock-based compensation expense | $ |
|
$ 2,375
|
$ 885
|
$ 622
|
|
|
|
| Number of Shares, Granted |
|
2,360,682
|
|
|
|
|
|
| Weighted-Average Exercise Price, Options exercisable | $ / shares |
|
$ 5.56
|
|
|
|
|
|
| Number of Shares, Options expected to vest |
|
2,336,878
|
|
|
|
|
|
| 2007 Stock Incentive Plan [Member] |
|
|
|
|
|
|
|
| Share Based Compensation Arrangement By Share Based Payment Award [Line Items] |
|
|
|
|
|
|
|
| Maximum shares of common stock provided under stock incentive plan |
|
|
|
|
|
|
1,275,211
|
| Stock options vesting period |
|
4 years
|
|
|
|
|
|
| Stock options expiration period |
|
10 years
|
|
|
|
|
|
| Shares available for future grant |
|
0
|
0
|
|
|
|
|
| 2014 Stock Incentive Plan [Member] |
|
|
|
|
|
|
|
| Share Based Compensation Arrangement By Share Based Payment Award [Line Items] |
|
|
|
|
|
|
|
| Maximum shares of common stock provided under stock incentive plan |
|
|
|
|
|
1,000,000
|
|
| Stock options vesting period |
|
3 years
|
|
|
|
|
|
| Shares available for future grant |
|
540,950
|
|
|
|
|
|
| Percentage of common stock outstanding stock on first day of the year |
|
|
|
|
|
4.00%
|
|
| Total intrinsic value of stock options exercised | $ |
|
$ 0
|
$ 161
|
$ 15
|
|
|
|
| Weighted-average per share grant date fair value of options granted | $ / shares |
|
$ 3.22
|
$ 3.33
|
$ 2.90
|
|
|
|
| Unrecognized compensation cost related to unvested stock-based compensation arrangements | $ |
|
$ 6,100
|
|
|
|
|
|
| Weighted-average period of recognition of unrecognized compensation cost related to unvested stock-based compensation arrangements |
|
2 years 10 months 17 days
|
|
|
|
|
|
| Number of Shares, Options expected to vest |
|
16,000
|
|
|
|
|
|
| 2014 Stock Incentive Plan [Member] | CEO [Member] |
|
|
|
|
|
|
|
| Share Based Compensation Arrangement By Share Based Payment Award [Line Items] |
|
|
|
|
|
|
|
| Number of Shares, Granted |
|
|
|
|
60,934
|
|
|
| 2014 Stock Incentive Plan [Member] | Non Employee Awards [Member] |
|
|
|
|
|
|
|
| Share Based Compensation Arrangement By Share Based Payment Award [Line Items] |
|
|
|
|
|
|
|
| Weighted-average per share grant date fair value of options granted | $ / shares |
$ 2.71
|
$ 1.58
|
|
|
|
|
|
| Stock-based compensation expense | $ |
|
$ 173
|
$ 56
|
$ 85
|
|
|
|
| Number of Shares, Granted |
90,000
|
204,000
|
0
|
0
|
|
|
|
| Weighted-Average Exercise Price, Options exercisable | $ / shares |
$ 4.71
|
$ 5.17
|
|
|
|
|
|
| 2014 Employee Stock Purchase Plan [Member] |
|
|
|
|
|
|
|
| Share Based Compensation Arrangement By Share Based Payment Award [Line Items] |
|
|
|
|
|
|
|
| Maximum shares of common stock provided under stock incentive plan |
|
500,000
|
|
|
|
600,000
|
|
| Percentage of common stock outstanding stock on first day of the year |
|
|
|
|
|
1.00%
|
|
| Stock-based compensation expense | $ |
|
$ 27
|
$ 0
|
|
|
|
|
| Offering period |
|
6 months
|
|
|
|
|
|
| Number of Offerings Per Year | Offering Period |
|
2
|
|
|
|
|
|