Retirement Benefits and Trusteed Assets Retirement Benefits and Trusted Assets (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Pension Plans, Defined Benefit [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Service Cost	$ 17	$ 19
Interest Cost	40	36
Expected Return on Plan Assets	(48)	(46)
Amortization of Net Acutuarial Losses	27	36
Amortization of Prior Service Cost (Credit)	0	0
Net Periodic Benefit Cost	36	45
Other Postretirement Benefit Plans, Defined Benefit [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Service Cost	7	12
Interest Cost	17	18
Expected Return on Plan Assets	(21)	(18)
Amortization of Net Acutuarial Losses	3	12
Amortization of Prior Service Cost (Credit)	(27)	(17)
Net Periodic Benefit Cost	$ (21)	$ 7