Derivatives and Risk Management (Details 2) (USD $) In Millions, unless otherwise specified	12 Months Ended
Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Derivative Instruments, Gain (Loss) [Line Items]
Cash Flow Hedge Gain to be Reclassified within Twelve Months	$ 157
Effective Portion Reclassified from AOCI to Earnings	135	(15)	172
Effective Portion Recognized in Other Comprehensive Income (Loss)	161	211	(167)
Fuel Contract [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Effective Portion Reclassified from AOCI to Earnings	0	15	233
Effective Portion Recognized in Other Comprehensive Income (Loss)	0	(15)	(166)
Interest Rate Contract [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Effective Portion Reclassified from AOCI to Earnings	0	(5)	0
Effective Portion Recognized in Other Comprehensive Income (Loss)	28	14	(8)
Foreign Exchange Contract [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Effective Portion Reclassified from AOCI to Earnings	135	(25)	(61)
Effective Portion Recognized in Other Comprehensive Income (Loss)	$ 133	$ 212	$ 7

The estimated net amount of existing gains or losses on cash flow hedges at the reporting date expected to be reclassified to earnings within the next 12 months.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 815

-SubTopic 30

-Section 50

-Paragraph 1

-Subparagraph (c)

-URI http://asc.fasb.org/extlink&oid=7668309&loc=d3e80748-113994

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- Definition

The effective portion of net gain (loss) reclassified from accumulated other comprehensive income into income on derivative instruments designated and qualifying as hedging instruments.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 815

-SubTopic 10

-Section 50

-Paragraph 4C

-Subparagraph (c)

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

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 815

-SubTopic 10

-Section 50

-Paragraph 4D

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=7476318&loc=SL5624177-113959

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- Definition

The effective portion of gains and losses (net) on derivative instruments designated and qualifying as hedging instruments that was recognized in other comprehensive income during the current period.

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