Significant Accounting Policies - Computer Software (Details) - Computer software |
12 Months Ended |
|---|---|
Dec. 31, 2016 | |
| Minimum | |
| Property, Plant and Equipment [Line Items] | |
| Useful life | 3 years |
| Maximum | |
| Property, Plant and Equipment [Line Items] | |
| Useful life | 5 years |