Stock-Based Compensation (Schedule Of Assumptions To Value SOSAR Awards Granted) (Details) - $ / shares |
12 Months Ended | ||
---|---|---|---|
Dec. 31, 2018 |
Dec. 31, 2017 |
Dec. 31, 2016 |
|
Risk-free interest rate | 2.40% | 1.60% | 1.00% |
Expected life | 3 years 10 months 24 days | 3 years 8 months 12 days | 3 years 6 months |
Expected dividend yield | 0.00% | 0.00% | 0.00% |
Volatility | 32.20% | 29.90% | 32.20% |
Performance Shares [Member] | |||
Risk-free interest rate | 1.50% | 0.90% | |
Expected life | 3 years | 3 years | |
Expected dividend yield | 0.00% | 0.00% | |
Volatility | 29.90% | 31.40% | |
SOSARS [Member] | |||
Weighted-average grant date fair value | $ 77.61 | $ 105.97 | $ 117.48 |