Equity Compensation (Expense) (Details) - USD ($)
$ in Thousands |
12 Months Ended |
Dec. 31, 2017 |
Dec. 31, 2016 |
Dec. 31, 2015 |
| Stock options |
|
|
|
| Total stock-based compensation expense |
|
|
|
| Total stock-based compensation expense |
$ 12,105
|
$ 8,370
|
$ 7,034
|
| Total unrecognized compensation cost related to non-vested stock option awards |
$ 2,500
|
|
|
| Weighted-average period over which unrecognized compensation cost will be recognized |
1 year
|
|
|
| Stock options | Cost of revenue |
|
|
|
| Total stock-based compensation expense |
|
|
|
| Total stock-based compensation expense |
$ 251
|
171
|
174
|
| Stock options | Research and development |
|
|
|
| Total stock-based compensation expense |
|
|
|
| Total stock-based compensation expense |
4,242
|
3,256
|
2,885
|
| Stock options | Sales and marketing |
|
|
|
| Total stock-based compensation expense |
|
|
|
| Total stock-based compensation expense |
3,662
|
2,273
|
1,783
|
| Stock options | General and administrative |
|
|
|
| Total stock-based compensation expense |
|
|
|
| Total stock-based compensation expense |
3,950
|
$ 2,670
|
$ 2,192
|
| Restricted stock units |
|
|
|
| Total stock-based compensation expense |
|
|
|
| Total unrecognized compensation cost related to non-vested stock option awards |
$ 8,400
|
|
|
| Weighted-average period over which unrecognized compensation cost will be recognized |
1 year 8 months 12 days
|
|
|