Retirement Benefits and Trusteed Assets (Pension Plan - Benefits related to Qualified and Nonqualified Pension Plans Expected to be paid in the Next Ten Years) (Details) (Pension Plans, Defined Benefit [Member], USD $) In Millions, unless otherwise specified	Dec. 31, 2013
Pension Plans, Defined Benefit [Member]
Pension Benefits to be Paid Over the Next 5 Years and Thereafter [Line Items]
Defined Benefit Plan, Expected Future Benefit Payments, Next Twelve Months	$ 187
Defined Benefit Plan, Expected Future Benefit Payments, Year Two	193
Defined Benefit Plan, Expected Future Benefit Payments, Year Three	200
Defined Benefit Plan, Expected Future Benefit Payments, Year Four	208
Defined Benefit Plan, Expected Future Benefit Payments, Year Five	216
Defined Benefit Plan, Expected Future Benefit Payments, Five Fiscal Years Thereafter	1,182
Total Defined Benefit Pension Plan Expected Future Payments	$ 2,186