Stock-Based Compensation Schedule of Weighted Average Assumptions (Details) - $ / shares |
9 Months Ended | |
|---|---|---|
Sep. 30, 2015 |
Sep. 30, 2014 |
|
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | ||
| Volatility | 23.85% | 32.84% |
| Risk-free interest rate | 1.88% | 2.16% |
| Expected term (years) | 6 years 6 months | 6 years 6 months |
| Dividend yield | 0.00% | 0.00% |
| Grant-date fair value | $ 5.74 | $ 5.15 |