Employee Benefits (Weighted Average Assumptions Used To Determine Postretirement Benefit Expense And Obligation) (Details)	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010
Expense [Member]
Defined Benefit Plan Disclosure [Line Items]
Discount rate	5.50%	6.10%
Current medical cost trend rate	8.00%	9.00%
Ultimate medical cost trend rate	4.75%	4.75%
Medical cost trend rate decreases to ultimate rate in year	2016	2016
Liability [Member]
Defined Benefit Plan Disclosure [Line Items]
Discount rate	4.60%	5.50%
Current medical cost trend rate	7.00%	8.00%
Ultimate medical cost trend rate	4.75%	4.75%
Medical cost trend rate decreases to ultimate rate in year	2021	2016