Postretirement Plans (Schedule Of Asset Allocations Of Postretirement Benefit Plans) (Details)	12 Months Ended
	Dec. 31, 2011
Cash And Cash Equivalents [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Target Allocation Percentage Of Assets, Other, Range Minimum	0.00%
Defined Benefit Plan, Target Allocation Percentage Of Assets, Other, Range Maximum	30.00%
Equity Securities [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Target Allocation Percentage of Assets, Equity Securities, Range Minimum	10.00%
Defined Benefit Plan, Target Allocation Percentage of Assets, Equity Securities, Range Maximum	55.00%
Fixed Income [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Target Allocation Percentage Of Assets, Other, Range Minimum	10.00%
Defined Benefit Plan, Target Allocation Percentage Of Assets, Other, Range Maximum	60.00%
Private Equity Funds [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Target Allocation Percentage Of Assets, Other, Range Minimum	0.00%
Defined Benefit Plan, Target Allocation Percentage Of Assets, Other, Range Maximum	15.00%
Real Estate Funds [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Target Allocation Percentage Of Assets, Other, Range Minimum	0.00%
Defined Benefit Plan, Target Allocation Percentage Of Assets, Other, Range Maximum	10.00%
Hedge Funds [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Target Allocation Percentage Of Assets, Other, Range Minimum	0.00%
Defined Benefit Plan, Target Allocation Percentage Of Assets, Other, Range Maximum	20.00%
Commodities [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Target Allocation Percentage Of Assets, Other, Range Minimum	0.00%
Defined Benefit Plan, Target Allocation Percentage Of Assets, Other, Range Maximum	25.00%