Retirement Benefits (Details 12) (USD $) In Millions, unless otherwise specified	Dec. 31, 2012
Pension Benefits
Estimated Benefit Payments (Table Amounts) [Abstract]
2013	$ 1,291
2014	1,347
2015	1,402
2016	1,454
2017	1,507
2018 through 2022	8,410
Medical and Life Benefits
Estimated Benefit Payments (Table Amounts) [Abstract]
2013	147
2014	153
2015	157
2016	160
2017	162
2018 through 2022	$ 829

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Amount of benefits expected to be paid in the five fiscal years after the fifth fiscal year following the latest fiscal year from a defined benefit plan.

+ 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 (f)

-URI http://asc.fasb.org/extlink&oid=21915506&loc=d3e1928-114920

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Amount of benefits expected to be paid in the next fiscal year following the latest fiscal year from a defined benefit plan.

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Amount of benefits expected to be paid in the fifth fiscal year following the latest fiscal year from a defined benefit plan.

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Amount of benefits expected to be paid in the fourth fiscal year following the latest fiscal year from a defined benefit plan.

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Amount of benefits expected to be paid in the third fiscal year following the latest fiscal year from a defined benefit plan.

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Amount of benefits expected to be paid in the second fiscal year following the latest fiscal year from a defined benefit plan.

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