FAIR VALUE MEASUREMENTS (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2011 Years		Sep. 30, 2011 Years		Dec. 31, 2010
Notes to Financial Statements [Abstract]
Auction frequency	30-35 days
Available For Sale Securities Unrealized Loss	$ 15		$ 15
Auction Rate Securities, Lower Remaining Maturity Range	7		7
Auction Rate Securities, Higher Remaining Maturity Range	36		36
Auction Rate Securities at Time of First Failed Auctions	463		463
Auction Rate Securities Sold At Par After Failed Auctions	367		367
ASSETS [Abstract]
Cash equivalents	891	[1]	891	[1]	1,261
Commercial paper 1	117		117
Certificates of deposit, cash equivalent	8		8
Short-term Investments [Abstract]
Treasury bills	2,354		2,354		2,010
Certificates of deposit, current	226		226		267
Commercial paper 2	60		60
Noncurrent investments [Abstract]
Auction rate securities	81	[2]	81	[2]
Certificates of deposit, noncurrent	25	[2]	25	[2]
Noncurrent investments					93	[3]
Interest rate derivatives 1	64		64		73
Fuel derivative assets [Abstract]
Swap contracts, net liabilities 1	0		0		33	[4]
Option contracts, net liabilities 1	0		0		233	[4]
Swap contracts, net assets 1	216	[4]	216	[4]	286	[5]
Option contracts, net assets 1	582	[4]	582	[4]	788	[5]
Other available-for-sale securities	5		5		39
Total assets	4,629		4,629		5,083
Fuel derivative liability [Abstract]
Swap contracts, net liabilities 2	0		0		387	[4]
Option contracts, net liabilities 2	0		0		119	[4]
Swap contracts, net assets 2	440	[4]	440	[4]	476	[5]
Option contracts, net assets 2	1,015	[4]	1,015	[4]	216	[5]
Interest rate derivatives 2	130		130		4
Total liabilities	1,585		1,585		1,202
Fair Value Measurements Using Significant Unobservable Inputs (Level 3) [Roll Forward]
Beginning balance	935		784
Total gains or (losses) (realized or unrealized) [Abstract]
Included in earnings	(635)		(438)
Included in other comprehensive income	(627)		(437)
Purchases	105		425
Sales	(93)		(513)
Settlements	(32)		(168)
Ending balance	(347)		(347)
The amount of total gains or (losses) for the period included in earnings attributable to the change in unrealized gains or losses relating to assets still held at balance sheet date	(614)		(405)
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
ASSETS [Abstract]
Cash equivalents	891	[1]	891	[1]	1,261
Commercial paper 1	0		0
Certificates of deposit, cash equivalent	0		0
Short-term Investments [Abstract]
Treasury bills	2,354		2,354		2,010
Certificates of deposit, current	0		0		0
Commercial paper 2	0		0
Noncurrent investments [Abstract]
Auction rate securities	0	[2]	0	[2]
Certificates of deposit, noncurrent	0	[2]	0	[2]
Noncurrent investments					0	[3]
Interest rate derivatives 1	0		0		0
Fuel derivative assets [Abstract]
Swap contracts, net liabilities 1	0		0		0	[4]
Option contracts, net liabilities 1	0		0		0	[4]
Swap contracts, net assets 1	0	[4]	0	[4]	0	[5]
Option contracts, net assets 1	0	[4]	0	[4]	0	[5]
Other available-for-sale securities	0		0		34
Total assets	3,245		3,245		3,305
Fuel derivative liability [Abstract]
Swap contracts, net liabilities 2	0		0		0	[4]
Option contracts, net liabilities 2	0		0		0	[4]
Swap contracts, net assets 2	0	[4]	0	[4]	0	[5]
Option contracts, net assets 2	0	[4]	0	[4]	0	[5]
Interest rate derivatives 2	0		0		0
Total liabilities	0		0		0
Significant Other Observable Inputs (Level 2) [Member]
ASSETS [Abstract]
Cash equivalents	0	[1]	0	[1]	0
Commercial paper 1	117		117
Certificates of deposit, cash equivalent	8		8
Short-term Investments [Abstract]
Treasury bills	0		0		0
Certificates of deposit, current	226		226		267
Commercial paper 2	60		60
Noncurrent investments [Abstract]
Auction rate securities	0	[2]	0	[2]
Certificates of deposit, noncurrent	25	[2]	25	[2]
Noncurrent investments					0	[3]
Interest rate derivatives 1	64		64		73
Fuel derivative assets [Abstract]
Swap contracts, net liabilities 1	0		0		33	[4]
Option contracts, net liabilities 1	0		0		0	[4]
Swap contracts, net assets 1	216	[4]	216	[4]	286	[5]
Option contracts, net assets 1	0	[4]	0	[4]	0	[5]
Other available-for-sale securities	0		0		0
Total assets	716		716		659
Fuel derivative liability [Abstract]
Swap contracts, net liabilities 2	0		0		387	[4]
Option contracts, net liabilities 2	0		0		0	[4]
Swap contracts, net assets 2	440	[4]	440	[4]	476	[5]
Option contracts, net assets 2	0	[4]	0	[4]	0	[5]
Interest rate derivatives 2	130		130		4
Total liabilities	570		570		867
Significant Unobservable Inputs (Level 3) [Member]
ASSETS [Abstract]
Cash equivalents	0	[1]	0	[1]	0
Commercial paper 1	0		0
Certificates of deposit, cash equivalent	0		0
Short-term Investments [Abstract]
Treasury bills	0		0		0
Certificates of deposit, current	0		0		0
Commercial paper 2	0		0
Noncurrent investments [Abstract]
Auction rate securities	81	[2]	81	[2]
Certificates of deposit, noncurrent	0	[2]	0	[2]
Noncurrent investments					93	[3]
Interest rate derivatives 1	0		0		0
Fuel derivative assets [Abstract]
Swap contracts, net liabilities 1	0		0		0	[4]
Option contracts, net liabilities 1	0		0		233	[4]
Swap contracts, net assets 1	0	[4]	0	[4]	0	[5]
Option contracts, net assets 1	582	[4]	582	[4]	788	[5]
Other available-for-sale securities	5		5		5
Total assets	668		668		1,119
Fuel derivative liability [Abstract]
Swap contracts, net liabilities 2	0		0		0	[4]
Option contracts, net liabilities 2	0		0		119	[4]
Swap contracts, net assets 2	0	[4]	0	[4]	0	[5]
Option contracts, net assets 2	1,015	[4]	1,015	[4]	216	[5]
Interest rate derivatives 2	0		0		0
Total liabilities	1,015		1,015		335
Fuel Derivatives [Member]
Fair Value Measurements Using Significant Unobservable Inputs (Level 3) [Roll Forward]
Beginning balance	846		686
Total gains or (losses) (realized or unrealized) [Abstract]
Included in earnings			(438)
Included in other comprehensive income	(624)		(439)
Purchases	105		425
Sales	(93)		(499)
Settlements	(32)		(168)
Ending balance	(433)		(433)
The amount of total gains or (losses) for the period included in earnings attributable to the change in unrealized gains or losses relating to assets still held at balance sheet date	(614)		(405)
Auction Rate Securities [Member]
Fair Value Measurements Using Significant Unobservable Inputs (Level 3) [Roll Forward]
Beginning balance	84		93
Total gains or (losses) (realized or unrealized) [Abstract]
Included in earnings	0		0
Included in other comprehensive income	(3)		2
Purchases	0		0
Sales	0		(14)
Settlements	0		0
Ending balance	81		81
The amount of total gains or (losses) for the period included in earnings attributable to the change in unrealized gains or losses relating to assets still held at balance sheet date	0		0
Other Securities [Member]
Fair Value Measurements Using Significant Unobservable Inputs (Level 3) [Roll Forward]
Beginning balance	5		5
Total gains or (losses) (realized or unrealized) [Abstract]
Included in earnings	0		0
Included in other comprehensive income	0		0
Purchases	0		0
Sales	0		0
Settlements	0		0
Ending balance	5	[6],[7]	5	[6],[7]
The amount of total gains or (losses) for the period included in earnings attributable to the change in unrealized gains or losses relating to assets still held at balance sheet date	0		0
Carrying Value [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
10.5% Notes Due 2011	399		399
Term Loan Agreement due 2020 - 5.223%	496		496
Term Loan Agreement due 2019 - 6.64%	276		276
Term Loan Agreement due 2019 - 6.84%	105		105
French Credit Agreements due 2012	10		10
6.5% Notes due 2012	379		379
5.25% Notes due 2014	350		350
5.75% Notes due 2016	271		271
5.125% Notes due 2017	300		300
French Credit Agreements due 2017	69		69
Pass Through Certificates due 2022	411		411
7.375% Debentures due 2027	64		64
Floating-rate B737 aircraft notes payable through 2020	634		634
Notes Payable Aircraft Fixed Rate Through 2018	41		41
Notes Payable Aircraft Fixed Rate Through 2017	68		68
Convertible Debt Due 2016	120		120
Estimated Fair Value [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
10.5% Notes Due 2011	391		391
Term Loan Agreement due 2020 - 5.223%	447		447
Term Loan Agreement due 2019 - 6.64%	282		282
Term Loan Agreement due 2019 - 6.84%	114		114
French Credit Agreements due 2012	10		10
6.5% Notes due 2012	385		385
5.25% Notes due 2014	367		367
5.75% Notes due 2016	298		298
5.125% Notes due 2017	322		322
French Credit Agreements due 2017	69		69
Pass Through Certificates due 2022	420		420
7.375% Debentures due 2027	81		81
Floating-rate B737 aircraft notes payable through 2020	634		634
Notes Payable Aircraft Fixed Rate Through 2018	44		44
Notes Payable Aircraft Fixed Rate Through 2017	73		73
Convertible Debt Due 2016	$ 114		$ 114

[1] Cash equivalents is primarily composed of money market investments.

[2] Noncurrent investments are included in Other assets in the unaudited Condensed Consolidated Balance Sheet.

[3] Auction rate securities included in Other assets in the unaudited Condensed Consolidated Balance Sheet.

[4] In the unaudited Condensed Consolidated Balance Sheet, amounts are presented as a net liability, and are also net of cash collateral provided to counterparties. See Note 5.

[5] In the unaudited Condensed Consolidated Balance Sheet, amounts are presented as a net asset, and are also net of cash collateral received from or provided to counterparties. See Note 5.

[6] (a) Included in Other assets in the unaudited Condensed Consolidated Balance Sheet.

[7] * Represents the position of each trade before consideration of offsetting positions with each counterparty and does not include the impact of cash collateral deposits provided to or received from counterparties. See discussion of credit risk and collateral following in this Note.