Employee Benefit Plans and Other Postretirement Benefits (Schedule Of-Weighted Average Health Care Cost Trend Rate Assumption) (Details) - Postretirement Health Coverage $ in Thousands	12 Months Ended
	Dec. 31, 2016 USD ($)
Defined Benefit Plan, Effect of One-Percentage Point Change in Assumed Health Care Cost Trend Rates [Abstract]
Total of service and interest cost components in 2016, One Percent Increase	$ 658
Total of service and interest cost components in 2016, One Percent Decrease	(624)
Accumulated benefit obligation as of December 31, 2016, One Percent Increase	12,670
Accumulated benefit obligation as of December 31, 2016, One Percent Decrease	$ (11,443)