Retirement Benefits and Trusteed Assets (Details Textuals) (USD $)	12 Months Ended			1 Months Ended	12 Months Ended		1 Months Ended	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Jan. 31, 2012 Pension Plans, Defined Benefit [Member]	Dec. 31, 2012 Pension Plans, Defined Benefit [Member]	Dec. 31, 2011 Pension Plans, Defined Benefit [Member]	Jan. 31, 2012 Other Postretirement Benefit Plans, Defined Benefit [Member]	Dec. 31, 2012 Other Postretirement Benefit Plans, Defined Benefit [Member]	Dec. 31, 2011 Other Postretirement Benefit Plans, Defined Benefit [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Transfers between Level 2 and Level 3					$ 0			$ 0
Transfers between Level 1 and Level 2					0			0
Health Care Trend Increase in Percentage Point	0.00%
Defined Benefit Plan, Effect of One Percentage Point Increase On Service and Interest	21,000,000
Company contributions				275,000,000	208,000,000	204,000,000	120,000,000	95,000,000	66,000,000
Defined Contribution Plan, Cost Recognized	19,000,000	18,000,000	17,000,000
Defined Benefit Plan, Estimated Future Employer Contributions in Current Fiscal Year								120,000,000
Defined Benefit Plan, Effect of One Percentage Point Increase on Accumulated Postretirement Benefit Obligation	218,000,000
Health Care Trend Decrease in Percentage Point	0.00%
Defined Benefit Plan, Effect of One Percentage Point Decrease on Service and Interest Cost Components	13,000,000
Prescription Drug Benefit, Effect of Subsidy on Net Periodic Postretirement Benefit Cost	4,000,000	5,000,000	5,000,000
Time period to pay benefit payments for qualified and unqualified plans					5 years			5 years
Time period for aggregate benefit payments for qualified and non qualtified benefit plans					5 years			5 years
Allocation of Company Contributions in Lieu of Post-Employment Health Care Benefits	4,000
Time Period for Vesting of Allocation of Company Contributions in Lieu of Post-Employment Health Care Benefits	10 years
Company Retiree New Coverage Maximum	0
Company Retiree New Coverage Minimum	3,250
Company Retiree New Coverage after a Certain Date Maximum	4,000
Defined Benefit Plan Effect of One Percentage Point on Post Retirement Obligation	$ 185,000,000