Stock-based Compensation - Performance Share Unit Awards - General Information (Details) - Performance Share Unit Awards |
12 Months Ended |
|---|---|
Dec. 31, 2016 | |
| Stock-based Compensation | |
| Vesting term | 3 years |
| Class A common stock | |
| Stock-based Compensation | |
| Exchangeable ratio of vested performance unit (as a percent) | 1 |
| Class A common stock | Minimum | |
| Stock-based Compensation | |
| Number of shares of common stock issuable upon vesting of the performance unit awards (as a percent) | 0.00% |
| Class A common stock | Maximum | |
| Stock-based Compensation | |
| Number of shares of common stock issuable upon vesting of the performance unit awards (as a percent) | 200.00% |