DERIVATIVE INSTRUMENTS - OUTSTANDING FUEL HEDGE POSITIONS (DETAILS) (June 30, 2011 [Member], USD $)	Aug. 03, 2011 Third Quarter 2011 [Member] Forward Contracts [Member]	Jun. 30, 2011 Third Quarter 2011 [Member] Swap [Member]	Aug. 03, 2011 Fourth Quarter 2011 [Member] Forward Contracts [Member]	Jun. 30, 2011 Fourth Quarter 2011 [Member] Swap [Member]	Aug. 03, 2011 Remainder Of 2011 [Member] Forward Contracts [Member]	Aug. 03, 2011 First Quarter 2012 [Member] Forward Contracts [Member]	Aug. 03, 2011 Second Quarter 2012 [Member] Forward Contracts [Member]	Aug. 03, 2011 Third Quarter 2012 [Member] Forward Contracts [Member]	Aug. 03, 2011 Fourth Quarter 2012 [Member] Forward Contracts [Member]	Aug. 03, 2011 Full Year 2012 [Member] Forward Contracts [Member]	Aug. 03, 2011 First Quarter 2013 [Member] Forward Contracts [Member]	Aug. 03, 2011 Second Quarter 2013 [Member] Forward Contracts [Member]	Aug. 03, 2011 Third Quarter 2013 [Member] Forward Contracts [Member]	Aug. 03, 2011 Fourth Quarter 2013 [Member] Forward Contracts [Member]	Aug. 03, 2011 Full Year 2013 [Member] Forward Contracts [Member]	Aug. 03, 2011 First Quarter 2014 [Member] Forward Contracts [Member]	Aug. 03, 2011 Second Quarter 2014 [Member] Forward Contracts [Member]	Aug. 03, 2011 Full Year 2014 [Member] Forward Contracts [Member]
Derivative [Line Items]
Nonmonetary Notional Amount of Price Risk Derivatives	51,900,000		48,600,000		100,500,000	48,600,000	51,200,000	53,000,000	44,500,000	197,300,000	32,600,000	28,600,000	24,000,000	17,100,000	102,300,000	11,500,000	6,000,000	17,500,000
Derivative, Nonmonetary Notional Amount, Price Per Barrel	$ 86		$ 86		$ 86	$ 88	$ 93	$ 94	$ 93	$ 92	$ 93	$ 92	$ 95	$ 97	$ 94	$ 100	$ 99	$ 99
Derivative Nonmonetary Notional Amount Premium Cost Per Barrel	11		11		11	12	13	13	13	13	14	15	15	15	14	15	15	15
Derivative, Nonmonetary Notional Amount, Percent of Required Need, Coverage	50.00%	50.00%	50.00%	11.00%	50.00%	50.00%	50.00%	50.00%	44.00%	49.00%	33.00%	27.00%	22.00%	16.00%	24.00%	11.00%	6.00%	4.00%
Average jet fuel purchase price per gallon		$ 0.75		0.84

Derivative Nonmonetary Notional Amount Premium Cost Per Barrel

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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- Definition

The percentage of expected requirements covered by the aggregate notional amount of derivative contracts expressed in nonmonetary units. For example, the number of barrels specified in a fuel oil forward purchase contract as a percentage of expected need.

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- Definition

The price per barrel of the notional amount of the derivative contract expressed in nonmonetary units. For example, the price per barrel specified in a fuel oil forward purchase contract.

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- Definition

Average fixed price related to the group of price risk swap derivatives.

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- Definition

Aggregate notional amount of price risk derivatives for instruments with notional amounts expressed in nonmonetary units.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 1B
-URI http://asc.fasb.org/extlink&oid=6935481&loc=SL5580258-113959

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Notional Amount
-URI http://asc.fasb.org/extlink&oid=6519104

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 1A
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=6935481&loc=SL5579245-113959

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