Retirement Benefits and Trusteed Assets Retirement Benefits and Trusteed Assets (Details Textuals) (USD $)	3 Months Ended
	Mar. 31, 2013	Dec. 31, 2012
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Pension Contributions	$ 100,000,000
Contribution of Common Stock to Pension Plan	50,000,000
Retiree Health Care Allowance	3,250
Remeausrement Reduction to Post Retirement Benefit Obligation	192,000,000	335,000,000
Remeausrement Reduction to Post Retirement Benefit Obligation Liability	661,000,000	996,000,000
Remeasurement Decrease in Benefit Cost for Postretirement Plans	51,000,000
Annual Decrease in Other Postretirement Benefits Costs due to Remeasurement	23,000,000
Pension Plans, Defined Benefit [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Estimated Future Employer Contributions in Current Fiscal Year	175,000,000
Other Postretirement Benefit Plans, Defined Benefit [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Contributions by Employer	120,000,000
Defined Benefit Plan, Estimated Future Employer Contributions in Current Fiscal Year	$ 120,000,000
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Discount Rate	4.30%	4.15%