Summary of Significant Accounting Policies - Transaction Revenues (Details) |
12 Months Ended |
|---|---|
|
Dec. 31, 2015
subscription_arrangement_type
| |
| Property, Plant and Equipment [Line Items] | |
| Types of subscription arrangement | 3 |
| Minimum | |
| Property, Plant and Equipment [Line Items] | |
| Subscription fee arrangement term | 1 month |
| Maximum | |
| Property, Plant and Equipment [Line Items] | |
| Subscription fee arrangement term | 6 months |