Retirement Benefits and Trusteed Assets (Details Textuals) (USD $)	3 Months Ended	12 Months Ended
	Mar. 31, 2013	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Company contributions to employee savings plan		4.00%
Retiree Health Care Allowance will increase at lower of the rate of medical inflation or a set percentage		2.00%
Retiree Health Care Allowance	$ 3,250
Prescription Drug Benefit, Effect of Subsidy on Net Periodic Postretirement Benefit Cost		1,000,000	4,000,000	5,000,000
Defined Contribution Plan, Cost Recognized		21,000,000	19,000,000	18,000,000
Pension Plans, Defined Benefit [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Company contributions		282,000,000	208,000,000
Defined Benefit Plans, Estimated Future Employer Contributions in Next Fiscal Year		275,000,000
Defined Benefit Plan, Expected Return on Plan Assets		7.75%
Transfers between Level 3 and Level 2		0
Transfers between Level 2 and Level 1		0
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Discount Rate		4.95%	4.15%	5.00%
Other Postretirement Benefit Plans, Defined Benefit [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Company contributions		239,000,000	95,000,000
Defined Benefit Plans, Estimated Future Employer Contributions in Next Fiscal Year		120,000,000
Defined Benefit Plan, Expected Return on Plan Assets		8.00%
Transfers between Level 3 and Level 2		0
Transfers between Level 2 and Level 1		0
Company Retiree New Coverage Minimum		3,250
Company Retiree New Coverage Maximum		3,500
Defined Benefit Plan, Effect of One Percentage Point Increase on Service and Interest Cost Components		6,000,000
Defined Benefit Plan, Effect of One Percentage Point Increase on Accumulated Postretirement Benefit Obligation		79,000,000
Defined Benefit Plan, Effect of One Percentage Point Decrease on Service and Interest Cost Components		5,000,000
Defined Benefit Plan, Effect of One Percentage Point Decrease on Accumulated Postretirement Benefit Obligation		70,000,000
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Discount Rate	4.30%	4.95%	4.15%	5.00%
Retiree Healthcare Plan [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Contribution Plan, Cost Recognized		1,000,000	0
Qualified Plans [Member] | Pension Plans, Defined Benefit [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Company contributions		$ 275,000,000