Summary of Equity Award Activity (Detail) - Class A Common Stock
$ / shares in Units, $ in Thousands |
12 Months Ended |
|
Dec. 31, 2015
USD ($)
$ / shares
shares
|
|---|
| Options |
|
| Outstanding at January 1, 2015 | shares |
26,705,905
|
| Granted | shares |
4,677,500
|
| Exercised | shares |
0
|
| Forfeited/Canceled | shares |
(667,150)
|
| Expired | shares |
(4,986,667)
|
| Outstanding at December 31, 2015 | shares |
25,729,588
|
| Vested or expected to vest at December 31, 2015 | shares |
25,729,588
|
| Exercisable at December 31, 2015 | shares |
19,923,008
|
| Weighted- Average Exercise Price |
|
| Outstanding at January 1, 2015 | $ / shares |
$ 4.82
|
| Granted | $ / shares |
2.27
|
| Exercised | $ / shares |
0.00
|
| Forfeited/Canceled | $ / shares |
6.11
|
| Expired | $ / shares |
4.64
|
| Outstanding at December 31, 2015 | $ / shares |
4.36
|
| Vested or expected to vest at December 31, 2015 | $ / shares |
4.36
|
| Exercisable at December 31, 2015 | $ / shares |
$ 4.77
|
| Weighted average remaining contractual term |
|
| Outstanding at December 31, 2015 |
7 years
|
| Vested or expected to vest at December 31, 2015 |
7 years
|
| Exercisable at December 31, 2015 |
6 years 3 months 18 days
|
| Aggregate intrinsic value |
|
| Outstanding at December 31, 2015 | $ |
$ 570
|
| Vested or expected to vest at December 31, 2015 | $ |
10,669
|
| Exercisable at December 31, 2015 | $ |
$ 737
|