Stock-Based Compensation - Schedule of Weighted Average Assumptions (Details) - $ / shares |
12 Months Ended | ||
|---|---|---|---|
Dec. 31, 2017 |
Dec. 31, 2016 |
Dec. 31, 2015 |
|
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |||
| Expected life (in years) | 7 years | ||
| Non-Qualified Stock Options (NQO) | |||
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |||
| Expected volatility | 30.80% | 30.20% | 34.10% |
| Expected life (in years) | 7 years | 7 years | 7 years |
| Risk-free rates | 2.30% | 1.69% | 2.00% |
| Weighted-average grant date fair value per share (in dollars per share) | $ 8.48 | $ 7.06 | $ 12.42 |