Fair Value Measurements and Derivative Instruments (Details 12) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2012	Dec. 31, 2011
Derivative Instruments
Amount of Gain (Loss) Recognized in Income on Derivative	$ (1,519)	$ 23,548
Foreign exchange contracts \| Other income (expense)
Derivative Instruments
Amount of Gain (Loss) Recognized in Income on Derivative	7,152	4,633
Fuel contracts \| Fuel swaps \| Other income (expense)
Derivative Instruments
Amount of Gain (Loss) Recognized in Income on Derivative	(3,058)
Fuel contracts \| Options \| Other income (expense)
Derivative Instruments
Amount of Gain (Loss) Recognized in Income on Derivative	$ (5,613)	$ 18,915

Net gain (loss) from the increase (decrease) in fair value of derivative instrument not designated as hedging instrument.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 815

-SubTopic 10

-Section 50

-Paragraph 4C

-Subparagraph (e)

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

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 133

-Paragraph 45

-Subparagraph b(1)(b)

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration