Retirement Benefits and Trusteed Assets (Pension Plan - Pension Cost Inclusions) (Details) (Pension Plans, Defined Benefit [Member], USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Pension Plans, Defined Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 73	$ 64	$ 55
Interest cost	146	155	154
Expected return on plan assets	(184)	(166)	(168)
Amortization of net loss	148	124	99
Amortization of prior service cost	1	1	4
Settlements	0	2	2
Net pension or postretirement cost (benefit)	$ 184	$ 180	$ 146