Earnings Per Share - Summary of Shares Excluded From Diluted Earnings Per Share Calculation (Details) - shares shares in Thousands |
3 Months Ended | 6 Months Ended | ||
|---|---|---|---|---|
Jun. 30, 2018 |
Jun. 30, 2017 |
Jun. 30, 2018 |
Jun. 30, 2017 |
|
| Stock option awards | ||||
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | ||||
| Anti-diluted shares excluded from computation of earnings per share (in shares) | 643 | 1,498 | 407 | 818 |
| Common Stock Class C | Common Stock | ||||
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | ||||
| Anti-diluted shares excluded from computation of earnings per share (in shares) | 12,314 | 0 | 13,497 | 0 |
| Performance stock units | ||||
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | ||||
| Anti-diluted shares excluded from computation of earnings per share (in shares) | 155 | 0 | 77 | 0 |