Accounts Receivable (Schedule Of Accounts Receivable Under Long-Term Contracts) (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Contracts Receivable, Claims and Uncertain Amounts, Fiscal Year Maturity [Abstract]
Claims, Current	$ 26	$ 49
Claims, Noncurrent	63	209
Claims	89	258
Unbilled Receivables, Not Billable, Fiscal Year Maturity [Abstract]
Unbilled Receivables, Unbillable, Current	1,316	1,174
Unbilled Receivables, Unbillable, Noncurrent	730	498
Unbilled Receivables, Unbillable	$ 2,046	$ 1,672

Amount of billed or unbilled claims or other similar items subject to uncertainty concerning their determination or ultimate realization under long-term contracts.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.3(c)(3))

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 3

-Subparagraph c(3)

-Article 5

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Amount of billed or unbilled claims or other similar items subject to uncertainty concerning their determination or ultimate realization under long-term contracts that are expected to be collected after the next fiscal year.

+ References

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 3

-Subparagraph c(3), c(4)

-Article 5

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

-Publisher FASB

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Amount of unbilled receivables under long-term contracts that have not been billed and were not billable.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 910

-SubTopic 310

-Section 50

-Paragraph 2

-Subparagraph (a)

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Amount of unbilled receivables under long-term contracts that have not been billed and were not billable that are expected to be collected after the next fiscal year.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

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Amount of unbilled receivables under long-term contracts that have not been billed and were not billable that are expected to be collected in the next fiscal year.

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