Retirement Benefits and Trusteed Assets Retirement Benefits and Trusteed Assets Textuals (Details) (USD $) In Millions, except Share data in Thousands, unless otherwise specified	6 Months Ended
	Jun. 30, 2012
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
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	140
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