Other Post Retirement Employee Benefit Plans (Weighted Average Assumptions Used To Determine Benefit Obligations) (Details) (Other Post-Retirement Benefits)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011
Other Post-Retirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Discount rate	3.90%	4.50%
Medical trend rate - initial	7.50%	7.70%
Medical trend rate - grading period	16 years	17 years
Medical trend rate - ultimate	4.50%	4.50%