| Property, Plant, and Equipment, net - Deprecation Expense (Details) (USD $) In Thousands, unless otherwise specified | 3 Months Ended | 9 Months Ended | ||
|---|---|---|---|---|
| Sep. 30, 2014 | Sep. 30, 2013 | Sep. 30, 2014 | Sep. 30, 2013 | |
| Property, Plant and Equipment [Line Items] | ||||
| Total depreciation expense | $ 1,834 | $ 1,106 | $ 5,170 | $ 2,357 | 
| Cost of sales | ||||
| Property, Plant and Equipment [Line Items] | ||||
| Total depreciation expense | 567 | 546 | 2,197 | 1,256 | 
| Sales and marketing expenses | ||||
| Property, Plant and Equipment [Line Items] | ||||
| Total depreciation expense | 163 | 0 | 377 | 0 | 
| Product development | ||||
| Property, Plant and Equipment [Line Items] | ||||
| Total depreciation expense | 295 | 18 | 580 | 51 | 
| General and administrative | ||||
| Property, Plant and Equipment [Line Items] | ||||
| Total depreciation expense | $ 809 | $ 542 | $ 2,016 | $ 1,050 |