Stock incentive plans (Details 2) - USD ($) $ in Thousands |
12 Months Ended | ||
|---|---|---|---|
Dec. 31, 2015 |
Dec. 31, 2014 |
Dec. 31, 2013 |
|
| Recognized stock-based compensation expense | |||
| Total stock-based compensation | $ 9,398 | $ 7,164 | $ 4,506 |
| Stock-based compensation expense capitalized | 778 | 398 | |
| Network operations | |||
| Recognized stock-based compensation expense | |||
| Total stock-based compensation | 1,504 | 1,356 | 888 |
| Development and Technology | |||
| Recognized stock-based compensation expense | |||
| Total stock-based compensation | 731 | 600 | 380 |
| Selling and marketing | |||
| Recognized stock-based compensation expense | |||
| Total stock-based compensation | 3,411 | 2,017 | 1,045 |
| General and administrative | |||
| Recognized stock-based compensation expense | |||
| Total stock-based compensation | $ 3,752 | $ 3,191 | $ 2,193 |