Employee Retirement Benefits (Assumptions Used To Determine Benefit Obligations) (Details) (Defined Benefit Pension [Member])	Dec. 31, 2011	Dec. 31, 2010
Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Discount rate	4.25%	5.50%
Long-term rate of compensation increase	4.50%	4.50%
Other Post-Retirement Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Discount rate	4.25%	5.50%
Long-term rate of compensation increase	4.50%	4.50%