Other Post Retirement Employee Benefit Plans (Weighted Average Assumptions Used To Determine Benefit Obligations) (Details) (Other Post-Retirement Benefits [Member])	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010
Other Post-Retirement Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Discount rate	4.50%	5.20%
Medical trend rate - initial	7.70%	7.90%
Medical trend rate - grading period	17 years	18 years
Medical trend rate - ultimate	4.50%	4.50%