Financial Instruments And Risk Management (Narrative) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
Mar. 31, 2014 barrel	Mar. 31, 2013	Dec. 31, 2013
Derivative [Line Items]
Nonmonetary notional amount	15,000,000
Higher remaining maturity range	15 months
Amount of gain (loss) recognized in condensed consolidated statements of operations	$ (2)	$ 8
Price risk cash flow hedge derivative, at fair value	48		107
Estimate of time to transfer	12 months
Estimated net amount to be transferred	(3)
AA [Member]
Derivative [Line Items]
Nonmonetary notional amount	15,000,000
Higher remaining maturity range	15 months
Minimum R-squared percentage in fuel hedge contracts (percent)	80.00%
Minimum dollar offset correlation (percent)	80.00%
Maximum dollar offset correlation (percent)	125.00%
Amount of gain (loss) recognized in condensed consolidated statements of operations	(2)	8
Price risk cash flow hedge derivative, at fair value	48		107
Estimate of time to transfer	12 months
Estimated net amount to be transferred	$ (3)

Aggregate notional amount of derivative expressed in nonmonetary units. For example, the number of barrels specified in a fuel oil forward purchase contract.

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Article 12

-Section 13

-Sentence Column B

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- Definition

Amount of increase (decrease) in the fair value of derivatives recognized in the income statement.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 815

-SubTopic 10

-Section 50

-Paragraph 4A

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=7476318&loc=SL5618551-113959

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 815

-SubTopic 10

-Section 50

-Paragraph 4C

-Subparagraph (a),(c),(d),(e)

-URI http://asc.fasb.org/extlink&oid=7476318&loc=SL5624171-113959

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- Definition

High end period remaining until maturity for the derivative contract, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

No definition available.

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- Definition

The estimated value of gains (losses), net anticipated to be transferred in the future from accumulated other comprehensive income into earnings.

+ References

No definition available.

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Estimated period for the anticipated transfer of gain (loss), net, from accumulated other comprehensive income into earnings, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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No definition available.

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- Definition

The upper end of the range of quotients represented as a percentage derived by dividing the change in value of a hedging instrument by the change in the value of the hedged item over the assessment period.

+ References

No definition available.

+ Details

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- Definition

The lower end of the range of quotients represented as a percentage derived by dividing the change in value of a hedging instrument by the change in the value of the hedged item over the assessment period.

+ References

No definition available.

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- Definition

The correlation coefficient between the hypothetical instrument and the hedged item used in determination of the effectiveness of a hedging relationship.

+ References

No definition available.

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- Definition

Fair value as of the balance sheet date of all price risk derivatives designated as cash flow hedging instruments.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 815

-SubTopic 10

-Section 45

-Paragraph 5

-URI http://asc.fasb.org/extlink&oid=6945355&loc=d3e41228-113958

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