FAIR VALUE MEASUREMENTS (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended																			3 Months Ended	9 Months Ended						3 Months Ended		9 Months Ended
	Sep. 30, 2012 Years		Sep. 30, 2012 Years		Dec. 31, 2011		Mar. 31, 2008	Sep. 30, 2012 French Credit Agreements due 2012 [Member]	Sep. 30, 2012 5.25% Notes due 2014 [Member]	Sep. 30, 2012 5.75% Notes due 2016 [Member]	Sep. 30, 2012 5.25% Convertible Senior Notes Due 2016 [Member]	Sep. 30, 2012 5.125% Notes due 2017 [Member]	Sep. 30, 2012 Fixed-rate 717 aircraft notes payable through 2017 [Member]	Sep. 30, 2012 French Credit Agreements due 2018 [Member]	Sep. 30, 2012 Fixed-rate 737 aircraft notes payable through 2018 [Member]	Sep. 30, 2012 Term Loan Agreement due 2019 6.315% [Member]	Sep. 30, 2012 Term Loan Agreement due 2019 6.84% [Member]	Sep. 30, 2012 Term Loan Agreement due 2020-5.223% [Member]	Sep. 30, 2012 Floating-rate 737 aircraft notes payable through 2020 [Member]	Sep. 30, 2012 Pass Through Certificates [Member]	Sep. 30, 2012 7.375% Debentures due 2027 [Member]	Sep. 30, 2012 Fuel hedge derivatives [Member]	Sep. 30, 2012 Fuel hedge derivatives [Member]	Dec. 31, 2016 Fuel hedge derivatives [Member] Option Model [Member] Implied Volatility [Member]	Dec. 31, 2015 Fuel hedge derivatives [Member] Option Model [Member] Implied Volatility [Member]	Dec. 31, 2014 Fuel hedge derivatives [Member] Option Model [Member] Implied Volatility [Member]	Dec. 31, 2013 Fuel hedge derivatives [Member] Option Model [Member] Implied Volatility [Member]	Dec. 31, 2012 Fuel hedge derivatives [Member] Option Model [Member] Implied Volatility [Member]	Sep. 30, 2012 Auction Rate Securities [Member]		Sep. 30, 2012 Auction Rate Securities [Member]		Sep. 30, 2012 Auction Rate Securities [Member] Discounted Cash Flow [Member] Illiquidity Premium [Member]	Sep. 30, 2012 Auction Rate Securities [Member] Discounted Cash Flow [Member] Counterparty Credit Spread [Member]	Sep. 30, 2012 Auction Rate Securities [Member] Discounted Cash Flow [Member] Time To Principal Recovery [Member]	Sep. 30, 2012 Other Securities [Member]	Jun. 30, 2012 Other Securities [Member]	Dec. 31, 2011 Other Securities [Member]	Sep. 30, 2012 Swap [Member]		Dec. 31, 2011 Swap [Member]		Sep. 30, 2012 Options Held [Member]		Dec. 31, 2011 Options Held [Member]		Sep. 30, 2012 Cash Equivalents [Member]		Dec. 31, 2011 Cash Equivalents [Member]		Sep. 30, 2012 Commercial Paper, Cash Equivalent [Member]	Dec. 31, 2011 Commercial Paper, Cash Equivalent [Member]	Dec. 31, 2011 Certificates of Deposit, Cash Equivalent [Member]	Sep. 30, 2012 Certificates Of Deposit Current [Member]	Dec. 31, 2011 Certificates Of Deposit Current [Member]	Sep. 30, 2012 Commercial Paper, Current [Member]	Dec. 31, 2011 Commercial Paper, Current [Member]	Sep. 30, 2012 Auction Rate Securities [Member]		Dec. 31, 2011 Auction Rate Securities [Member]		Dec. 31, 2011 Certificates Of Deposit Noncurrent [Member]		Sep. 30, 2012 Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]	Dec. 31, 2011 Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]	Sep. 30, 2012 Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] Cash Equivalents [Member]		Dec. 31, 2011 Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] Cash Equivalents [Member]		Sep. 30, 2012 Significant Other Observable Inputs (Level 2) [Member]		Dec. 31, 2011 Significant Other Observable Inputs (Level 2) [Member]		Sep. 30, 2012 Significant Other Observable Inputs (Level 2) [Member] 5.25% Notes due 2014 [Member]	Sep. 30, 2012 Significant Other Observable Inputs (Level 2) [Member] 5.75% Notes due 2016 [Member]	Sep. 30, 2012 Significant Other Observable Inputs (Level 2) [Member] 5.25% Convertible Senior Notes Due 2016 [Member]	Sep. 30, 2012 Significant Other Observable Inputs (Level 2) [Member] 5.125% Notes due 2017 [Member]	Sep. 30, 2012 Significant Other Observable Inputs (Level 2) [Member] Fixed-rate 717 aircraft notes payable through 2017 [Member]	Sep. 30, 2012 Significant Other Observable Inputs (Level 2) [Member] Pass Through Certificates [Member]	Sep. 30, 2012 Significant Other Observable Inputs (Level 2) [Member] 7.375% Debentures due 2027 [Member]	Sep. 30, 2012 Significant Other Observable Inputs (Level 2) [Member] Swap [Member]		Dec. 31, 2011 Significant Other Observable Inputs (Level 2) [Member] Swap [Member]		Sep. 30, 2012 Significant Other Observable Inputs (Level 2) [Member] Commercial Paper, Cash Equivalent [Member]	Dec. 31, 2011 Significant Other Observable Inputs (Level 2) [Member] Commercial Paper, Cash Equivalent [Member]	Sep. 30, 2012 Significant Other Observable Inputs (Level 2) [Member] Certificates of Deposit, Cash Equivalent [Member]	Dec. 31, 2011 Significant Other Observable Inputs (Level 2) [Member] Certificates of Deposit, Cash Equivalent [Member]	Sep. 30, 2012 Significant Other Observable Inputs (Level 2) [Member] Certificates Of Deposit Current [Member]	Dec. 31, 2011 Significant Other Observable Inputs (Level 2) [Member] Certificates Of Deposit Current [Member]	Sep. 30, 2012 Significant Other Observable Inputs (Level 2) [Member] Commercial Paper, Current [Member]	Dec. 31, 2011 Significant Other Observable Inputs (Level 2) [Member] Commercial Paper, Current [Member]	Dec. 31, 2011 Significant Other Observable Inputs (Level 2) [Member] Certificates Of Deposit Noncurrent [Member]		Sep. 30, 2012 Significant Unobservable Inputs (Level 3) [Member]	Dec. 31, 2011 Significant Unobservable Inputs (Level 3) [Member]	Sep. 30, 2012 Significant Unobservable Inputs (Level 3) [Member] French Credit Agreements due 2012 [Member]	Sep. 30, 2012 Significant Unobservable Inputs (Level 3) [Member] French Credit Agreements due 2018 [Member]	Sep. 30, 2012 Significant Unobservable Inputs (Level 3) [Member] Fixed-rate 737 aircraft notes payable through 2018 [Member]	Sep. 30, 2012 Significant Unobservable Inputs (Level 3) [Member] Term Loan Agreement due 2019 6.315% [Member]	Sep. 30, 2012 Significant Unobservable Inputs (Level 3) [Member] Term Loan Agreement due 2019 6.84% [Member]	Sep. 30, 2012 Significant Unobservable Inputs (Level 3) [Member] Term Loan Agreement due 2020-5.223% [Member]	Sep. 30, 2012 Significant Unobservable Inputs (Level 3) [Member] Floating-rate 737 aircraft notes payable through 2020 [Member]	Sep. 30, 2012 Significant Unobservable Inputs (Level 3) [Member] Options Held [Member]		Dec. 31, 2011 Significant Unobservable Inputs (Level 3) [Member] Options Held [Member]		Sep. 30, 2012 Significant Unobservable Inputs (Level 3) [Member] Auction Rate Securities [Member]		Dec. 31, 2011 Significant Unobservable Inputs (Level 3) [Member] Auction Rate Securities [Member]
Notes to Financial Statements [Abstract]
Auction frequency	30-35 days
Available For Sale Securities Unrealized Loss	$ 13		$ 13
Auction Rate Securities, Lower Remaining Maturity Range (in years)	6		6
Auction Rate Securities, Higher Remaining Maturity Range (in years)	35		35
Auction Rate Securities at Failed Auctions							463
Auction Rate Securities Sold At Par After Failed Auctions	413
ASSETS [Abstract]
Cash and Cash Equivalents																																															986	[1]	774	[1]	160	48	7	22												986	[1]	774	[1]																160	48	22	7
Treasury Bills	1,824		1,824		2,014																																																											1,824	2,014
Investments																																																						243	221		80	37	[2]	67	[2]	25	[2]																										243	221		80	25	[2]														37	[2]	67	[2]
Interest rate derivatives	71	[3]	71	[3]	66	[3]																																																																71	[3]	66	[3]
Fuel derivative assets [Abstract]
Derivative Asset, Fair Value, Gross Asset	1,233	[4]	1,233	[4]	1,300	[4]																																	87	[5]			896	[5]	709	[5]																																			87	[5]																						896	[5]	709	[5]
Derivative Liability, Fair Value, Gross Asset																																							66	[6]	180	[6]	113	[6]	345	[6]																																			66	[6]	180	[6]																				113	[6]	345	[6]
Other available for sale securities	50		50		43																																																											45	38																														5	5
Total assets	4,555		4,555		4,579																																																											2,855	2,826					649		627																							1,051	1,126
Fuel derivative liability [Abstract]
Derivative Asset, Fair Value, Gross Liability																																							(32)	[5]	(65)	[5]	(716)	[5]	(371)	[5]																																			(32)	[5]	(65)	[5]																				(716)	[5]	(371)	[5]
Derivative Liability, Fair Value, Gross Liability	(1,161)	[4]	(1,161)	[4]	(1,410)	[4]																																	(212)	[6]	(576)	[6]	(69)	[6]	(266)	[6]																																			(212)	[6]	(576)	[6]																				(69)	[6]	(266)	[6]
Interest rate derivatives	(132)	[3]	(132)	[3]	(132)	[3]																																																																(132)	[3]	(132)	[3]
Deferred compensation	(134)		(134)		(121)																																																											(134)	(121)
Total Liabilities	(1,295)		(1,295)		(1,531)																																																											(134)	(121)					(376)		(773)																							(785)	(637)
Fair Value Measurements Using Significant Unobservable Inputs (Level 3) [Roll Forward]
Beginning balance	123		489																			64	417						54		67					5	5	5
Total gains or (losses) (realized or unrealized) [Abstract]
Included in earnings	(11)		(15)																			(11)	(15)
Included in other comprehensive income	265		32																			259	31						6		1
Purchases	79		408																			79	408
Sales	(144)		(548)																			(121)	(517)						(23)		(31)
Settlements	(46)		(100)																			(46)	(100)
Ending balance	266		266																			224	224						37	[7]	37	[7]				5	5	5
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	(17)		(16)																			(17)	(16)
Quantitative Information About Level 3 [Line Items]
Fair Value Measurement Range, Minimum																								20%	21%	22%	23%	16%					3%	1%	6
Fair Value Measurement Range, Maximum																								24%	26%	32%	38%	37%					5%	3%	8
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Notes Payable, Fair Value																																																																										384	369	119	364	62	444																				39				537
Loans Payable, Fair Value																																																																																151																	3	61		248	101	411
Carrying amount of debt								$ 3	$ 368	$ 333	$ 117	$ 331	$ 64	$ 61	$ 37	$ 248	$ 95	$ 460	$ 562	$ 394	$ 138

[1] (a) Cash equivalents are primarily composed of money market investments.

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

[3] See Note 5

[4] * 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.

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

[6] (d) 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.

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