Stockholders' Equity (Weighted Average Assumptions) (Details) - $ / shares |
3 Months Ended | 9 Months Ended | ||
|---|---|---|---|---|
Sep. 30, 2018 |
Jun. 30, 2018 |
Mar. 31, 2018 |
Sep. 30, 2018 |
|
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | ||||
| Risk-free interest rate | 1.72% | 1.61% | 1.44% | |
| Stock Options | ||||
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | ||||
| Dividend yield | 1.18% | |||
| Expected volatility | 27.08% | |||
| Risk-free interest rate | 2.65% | |||
| Expected holding period (years) | 5 years | |||
| Black-Scholes value (in dollars per share) | $ 6.38 | $ 6.38 | ||