Benefit Plans (Effects Of One-Percentage-Point Change In Assumed Health Care Cost Trend Rates) (Details)	12 Months Ended
	Dec. 31, 2012
Benefit Plans: [Abstract]
Effect on total of service and interest cost, One-Percentage-Point Increase	7.10%
Effect on total of service and interest cost, One-Percentage-Point Decrease	(6.00%)
Effect on postretirement benefit obligation, One-Percentage-Point Increase	6.80%
Effect on postretirement benefit obligation, One-Percentage-Point Decrease	(5.80%)