Retirement Benefits and Trusteed Assets Retirement Benefits and Trusteed Assets Textuals (Details) (USD $) In Millions, except Share data in Thousands, unless otherwise specified	9 Months Ended
	Sep. 30, 2012
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Pension Contributions	$ 100
Contribution of Common Stock to Pension Plan	80
Contribution of Common Stock to Pension Plan Shares	1,300
Contribution of Common Stock to Pension Plans Amount Per Share	$ 59.94
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	120
Other Postretirement Benefit 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	120
Defined Benefit Plan, Contributions by Employer	$ 140