Retirement Benefits (Summary of the U.S. and Non-U.S. Plan Investments Measured At Fair Value on a Recurring Basis) (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 14,879	$ 13,562
Transfers from Level 1 to Level 2		0
Identical Assets (Level 1) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	3,228	3,702
Observable Inputs (Level 2) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	10,122	8,353
Unobservable Inputs (Level 3) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	1,529	1,507
Common/Collective trusts [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	7,122	5,938
Common/Collective trusts [Member] | Identical Assets (Level 1) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	172	138
Common/Collective trusts [Member] | Observable Inputs (Level 2) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	6,766	5,649
Common/Collective trusts [Member] | Unobservable Inputs (Level 3) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	184	151
Corporate Obligations [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	2,941	2,334
Corporate Obligations [Member] | Identical Assets (Level 1) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Corporate Obligations [Member] | Observable Inputs (Level 2) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	2,938	2,330
Corporate Obligations [Member] | Unobservable Inputs (Level 3) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	3	4
Corporate stocks [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	2,094	2,440
Corporate stocks [Member] | Identical Assets (Level 1) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	2,087	2,434
Corporate stocks [Member] | Observable Inputs (Level 2) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	6	5
Corporate stocks [Member] | Unobservable Inputs (Level 3) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	1	1
Private equity/partnerships [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	727	801
Private equity/partnerships [Member] | Identical Assets (Level 1) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Private equity/partnerships [Member] | Observable Inputs (Level 2) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	2
Private equity/partnerships [Member] | Unobservable Inputs (Level 3) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	727	799
Government Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	371	352
Government Securities [Member] | Identical Assets (Level 1) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	10
Government Securities [Member] | Observable Inputs (Level 2) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	371	340
Government Securities [Member] | Unobservable Inputs (Level 3) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	2
Real Estate [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	381	319
Real Estate [Member] | Identical Assets (Level 1) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Real Estate [Member] | Observable Inputs (Level 2) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	6	7
Real Estate [Member] | Unobservable Inputs (Level 3) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	375	312
Short-term investment funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	736	839
Short-term investment funds [Member] | Identical Assets (Level 1) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	724	824
Short-term investment funds [Member] | Observable Inputs (Level 2) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	12	15
Short-term investment funds [Member] | Unobservable Inputs (Level 3) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Company common stock [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	229	261
Company common stock [Member] | Identical Assets (Level 1) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	229	261
Company common stock [Member] | Observable Inputs (Level 2) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Company common stock [Member] | Unobservable Inputs (Level 3) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Other Investments [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	278	278
Other Investments [Member] | Identical Assets (Level 1) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	16	35
Other Investments [Member] | Observable Inputs (Level 2) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	23	5
Other Investments [Member] | Unobservable Inputs (Level 3) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 239	$ 238