Stock-Based Compensation - Stock Option Activity (Details) - USD ($)
$ / shares in Units, $ in Thousands |
3 Months Ended |
6 Months Ended |
12 Months Ended |
Jun. 30, 2015 |
Jun. 30, 2014 |
Jun. 30, 2015 |
Jun. 30, 2014 |
Dec. 31, 2014 |
| Number of Options |
|
|
|
|
|
| Outstanding balance at beginning of period (in shares) |
|
|
3,425,117
|
|
|
| Granted (in shares) |
|
|
459,875
|
|
|
| Exercised (in shares) |
|
|
(368,474)
|
|
|
| Cancelled (in shares) |
|
|
(131,978)
|
|
|
| Outstanding balance at end of period (in shares) |
3,384,540
|
|
3,384,540
|
|
3,425,117
|
| Exercisable at end of period (in shares) |
1,542,487
|
|
1,542,487
|
|
|
| Vested and expected to vest at end of period (in shares) |
2,880,491
|
|
2,880,491
|
|
|
| Weighted Average Exercise Price |
|
|
|
|
|
| Outstanding balance at beginning of period (in usd per share) |
|
|
$ 7.51
|
|
|
| Granted (in usd per share) |
|
|
10.72
|
|
|
| Exercised (in usd per share) |
|
|
1.75
|
|
|
| Cancelled (in usd per share) |
|
|
10.67
|
|
|
| Outstanding balance at end of period (in usd per share) |
$ 8.45
|
|
8.45
|
|
$ 7.51
|
| Exercisable at end of period (in usd per share) |
5.38
|
|
5.38
|
|
|
| Vested and expected to vest at end of period (in usd per share) |
$ 8.13
|
|
$ 8.13
|
|
|
| Weighted Average Remaining Contractual Term |
|
|
|
|
|
| Outstanding balance at end of period (in years) |
|
|
8 years 2 months 23 days
|
|
8 years 4 months 10 days
|
| Exercisable at end of period (in years) |
|
|
7 years 3 months 18 days
|
|
|
| Vested and expected to vest at end of period (in years) |
|
|
8 years 1 month 10 days
|
|
|
| Aggregate Intrinsic Value |
|
|
|
|
|
| Outstanding balance at end of period |
$ 7,970
|
|
$ 7,970
|
|
$ 26,260
|
| Exercisable at end of period |
6,475
|
|
6,475
|
|
|
| Vested and expected to vest at end of period |
$ 7,388
|
|
$ 7,388
|
|
|
| Additional information |
|
|
|
|
|
| Weighted-average grant date fair value (in usd per share) |
$ 4.37
|
$ 6.90
|
$ 5.58
|
$ 6.55
|
|
| Unrecognized compensation cost related to nonvested share-based compensation arrangements |
$ 9,700
|
|
$ 9,700
|
|
|
| Intrinsic value of options exercised |
$ 1,100
|
$ 500
|
$ 3,500
|
$ 1,500
|
|
| Stock options |
|
|
|
|
|
| Additional information |
|
|
|
|
|
| Expected weighted-average period for recognition of unrecognized stock-based compensation costs (in years) |
|
|
2 years 1 month 28 days
|
|
|