Employee Benefits (Weighted-Average Actuarial Assumptions for Benefit Obligations - Retirement Plans) (Details)	12 Months Ended
	Dec. 31, 2011 Retirement Plans	Dec. 31, 2011 Retirement Income Plan Benefit Obligations	Dec. 31, 2010 Retirement Income Plan Benefit Obligations	Dec. 31, 2011 Supplement Retirement Plan Benefit Obligations	Dec. 31, 2010 Supplement Retirement Plan Benefit Obligations	Dec. 31, 2011 Excess Benefit Plan Benefit Obligations	Dec. 31, 2010 Excess Benefit Plan Benefit Obligations
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Discount rate		4.30%	5.40%	3.60%	4.60%	4.10%	5.30%
Rate of compensation increase		5.00%	5.00%			5.00%	5.00%
Defined Benefit Plan, Effect of One Percentage Point Increase on Discount Rate	1.00%
Defined Benefit Plan, Decrease in Projected Benefit Obiligation, Percentage	12.70%
Defined Benefit Plan, Effect of One Percentage Point Decrease on Discount Rate	1.00%
Defined Benefit Plan, Increase in Projected Benefit Obiligation, Percentage	15.80%