Retirement Benefits (Details 11) (USD $) In Millions, unless otherwise specified	12 Months Ended
Dec. 31, 2013	Dec. 31, 2012
Actual return on plan assets:
Fair value of plan assets at end of year	$ 25,273	$ 24,024
Level 3
Changes in Fair Value of Plan Assets, Significant Unobservable Inputs (Table Amounts) [Abstract]
Fair value of plan assets at beginning of year	5,028	5,338
Actual return on plan assets:
Unrealized gains (losses), net	358	(26)
Realized gains (losses), net	43	42
Purchases	1,629	1,105
Sales	(1,388)	(1,431)
Fair value of plan assets at end of year	5,670	5,028
High yield debt and Hedge funds \| Level 3
Changes in Fair Value of Plan Assets, Significant Unobservable Inputs (Table Amounts) [Abstract]
Fair value of plan assets at beginning of year	786	1,446
Actual return on plan assets:
Unrealized gains (losses), net	(16)	23
Realized gains (losses), net	43	47
Purchases	200	0
Sales	(191)	(730)
Fair value of plan assets at end of year	822	786
Private equities
Actual return on plan assets:
Fair value of plan assets at end of year	2,075	1,980
Private equities \| Level 3
Changes in Fair Value of Plan Assets, Significant Unobservable Inputs (Table Amounts) [Abstract]
Fair value of plan assets at beginning of year	1,980	2,098
Actual return on plan assets:
Unrealized gains (losses), net	112	(122)
Realized gains (losses), net	0	0
Purchases	666	259
Sales	(683)	(255)
Fair value of plan assets at end of year	2,075	1,980
Real estate
Actual return on plan assets:
Fair value of plan assets at end of year	2,767	2,256
Real estate \| Level 3
Changes in Fair Value of Plan Assets, Significant Unobservable Inputs (Table Amounts) [Abstract]
Fair value of plan assets at beginning of year	2,256	1,788
Actual return on plan assets:
Unrealized gains (losses), net	262	68
Realized gains (losses), net	0	0
Purchases	763	846
Sales	(514)	(446)
Fair value of plan assets at end of year	2,767	2,256
Other Investments \| Level 3
Changes in Fair Value of Plan Assets, Significant Unobservable Inputs (Table Amounts) [Abstract]
Fair value of plan assets at beginning of year	6	6
Actual return on plan assets:
Unrealized gains (losses), net	0	5
Realized gains (losses), net	0	(5)
Purchases	0	0
Sales	0	0
Fair value of plan assets at end of year	$ 6	$ 6

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Actual return on plan assets, separately identifying the amount related to assets sold during the period.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 715

-SubTopic 20

-Section 50

-Paragraph 1

-Subparagraph (d)(iv)(02)(A)

-URI http://asc.fasb.org/extlink&oid=28361610&loc=d3e1928-114920

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 715

-SubTopic 20

-Section 50

-Paragraph 5

-Subparagraph (c)(iv)(02)(A)

-URI http://asc.fasb.org/extlink&oid=28361610&loc=d3e2446-114920

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Actual return on plan assets, separately identifying the amount related to assets still held at the reporting date.

+ References

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- Definition

The amount of increase in the plan assets attributed to a business combination.

+ References

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The amount of decrease in the plan assets attributed to the sale, liquidation, spin-off or other divestiture of a corporate division or subsidiary.

+ References

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Assets, usually stocks, bonds, and other investments, that have been segregated and restricted (usually in a trust) to provide benefits, at their fair value as of the measurement date. Plan assets include amounts contributed by the employer (and by employees for a contributory plan) and amounts earned from investing the contributions, less benefits paid. If a plan has liabilities other than for benefits, those non-benefit obligations may be considered as reductions of plan assets.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 715

-SubTopic 20

-Section 50

-Paragraph 1

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=28361610&loc=d3e1928-114920

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 715

-SubTopic 30

-Section 35

-Paragraph 50

-URI http://asc.fasb.org/extlink&oid=29635418&loc=d3e12355-114930

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