OPERATING SEGMENT INFORMATION (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Operating Revenues
Revenue from Contract with Customer, Excluding Assessed Tax	$ 2,828	$ 1,953	$ 7,167	$ 4,277
Operating expenses
Operating Expenses, Excluding Fuel	1,889	1,319	5,120	2,778
Economic fuel	877	376	2,000	853
Total Operating Expenses	2,766	1,695	7,120	3,631
Nonoperating Income (Expense)
Interest income	17	6	35	19
Interest expense	(31)	(30)	(84)	(101)
Interest capitalized	3	3	8	9
Other—net	14	8	38	27
Nonoperating Income (Expense)	3	(13)	(3)	(46)
Costs and Expenses, Total	$ 2,766	$ 1,695	$ 7,120	$ 3,631
Pretax Margin, Adjusted	15.60%	12.10%	8.00%	(9.10%)
Pretax Margin, GAAP	2.30%	12.50%	0.60%	14.00%
Mileage Plan Revenue [Member]
Operating Revenues
Revenue from Contract with Customer, Excluding Assessed Tax	$ 382	$ 310	$ 1,104	$ 760
Air Group Adjusted [Member]
Operating Revenues
Revenue from Contract with Customer, Excluding Assessed Tax	2,828	1,953	7,167	4,277
Operating expenses
Operating Expenses, Excluding Fuel	1,644	1,328	4,654	3,699
Economic fuel	746	376	1,936	921
Total Operating Expenses	2,390	1,704	6,590	4,620
Nonoperating Income (Expense)
Nonoperating Income (Expense)	3	(13)	(3)	(46)
Income (loss) before income tax	441	236	574	(389)
Alaska Mainline [Member]
Operating Revenues
Revenue from Contract with Customer, Excluding Assessed Tax	2,415	1,588	6,066	3,447
Operating expenses
Operating Expenses, Excluding Fuel	1,352	1,060	3,808	2,937
Economic fuel	625	299	1,623	726
Total Operating Expenses	1,977	1,359	5,431	3,663
Nonoperating Income (Expense)
Nonoperating Income (Expense)	8	(8)	12	(31)
Income (loss) before income tax	446	221	647	(247)
Alaska Regional [Member]
Operating Revenues
Revenue from Contract with Customer, Excluding Assessed Tax	411	364	1,097	827
Operating expenses
Operating Expenses, Excluding Fuel	292	288	843	839
Economic fuel	121	77	313	195
Total Operating Expenses	413	365	1,156	1,034
Nonoperating Income (Expense)
Nonoperating Income (Expense)	0	0	0	0
Income (loss) before income tax	(2)	(1)	(59)	(207)
Horizon [Member]
Operating Revenues
Revenue from Contract with Customer, Excluding Assessed Tax	93	107	288	322
Operating expenses
Operating Expenses, Excluding Fuel	94	93	291	272
Economic fuel	0	0	0	0
Total Operating Expenses	94	93	291	272
Nonoperating Income (Expense)
Nonoperating Income (Expense)	(5)	(6)	(15)	(16)
Income (loss) before income tax	(6)	8	(18)	34
Consolidating and Other [Member]
Operating Revenues
Revenue from Contract with Customer, Excluding Assessed Tax	(91)	(106)	(284)	(319)
Operating expenses
Operating Expenses, Excluding Fuel	(94)	(113)	(288)	(349)
Economic fuel	0	0	0	0
Total Operating Expenses	(94)	(113)	(288)	(349)
Nonoperating Income (Expense)
Nonoperating Income (Expense)	0	1	0	1
Income (loss) before income tax	3	8	4	31
Special Charges [Member]
Operating Revenues
Revenue from Contract with Customer, Excluding Assessed Tax	0	0	0	0
Operating expenses
Operating Expenses, Excluding Fuel	245	(9)	466	(921)
Economic fuel	131	0	64	(68)
Total Operating Expenses	376	(9)	530	(989)
Nonoperating Income (Expense)
Nonoperating Income (Expense)	0	0	0	0
Income (loss) before income tax	(376)	9	(530)	989
Passenger [Member]
Operating Revenues
Revenue from Contract with Customer, Excluding Assessed Tax	2,615	1,774	6,544	3,785
Passenger [Member] | Air Group Adjusted [Member]
Operating Revenues
Revenue from Contract with Customer, Excluding Assessed Tax	2,615	1,774	6,544	3,785
Passenger [Member] | Alaska Mainline [Member]
Operating Revenues
Revenue from Contract with Customer, Excluding Assessed Tax	2,217	1,425	5,488	3,003
Passenger [Member] | Alaska Regional [Member]
Operating Revenues
Revenue from Contract with Customer, Excluding Assessed Tax	398	349	1,056	782
Passenger [Member] | Horizon [Member]
Operating Revenues
Revenue from Contract with Customer, Excluding Assessed Tax	0	0	0	0
Passenger [Member] | Consolidating and Other [Member]
Operating Revenues
Revenue from Contract with Customer, Excluding Assessed Tax	0	0	0	0
Passenger [Member] | Special Charges [Member]
Operating Revenues
Revenue from Contract with Customer, Excluding Assessed Tax	0	0	0	0
Capacity Purchase Agreements [Member]
Operating Revenues
Revenue from Contract with Customer, Excluding Assessed Tax	0	0	0	0
Capacity Purchase Agreements [Member] | Air Group Adjusted [Member]
Operating Revenues
Revenue from Contract with Customer, Excluding Assessed Tax	0	0	0	0
Capacity Purchase Agreements [Member] | Alaska Mainline [Member]
Operating Revenues
Revenue from Contract with Customer, Excluding Assessed Tax	0	0	0	0
Capacity Purchase Agreements [Member] | Alaska Regional [Member]
Operating Revenues
Revenue from Contract with Customer, Excluding Assessed Tax	0	0	0	0
Capacity Purchase Agreements [Member] | Horizon [Member]
Operating Revenues
Revenue from Contract with Customer, Excluding Assessed Tax	93	107	288	322
Capacity Purchase Agreements [Member] | Consolidating and Other [Member]
Operating Revenues
Revenue from Contract with Customer, Excluding Assessed Tax	(93)	(107)	(288)	(322)
Capacity Purchase Agreements [Member] | Special Charges [Member]
Operating Revenues
Revenue from Contract with Customer, Excluding Assessed Tax	0	0	0	0
Mileage plan other revenue [Member]
Operating Revenues
Revenue from Contract with Customer, Excluding Assessed Tax	146	120	433	332
Mileage plan other revenue [Member] | Mileage Plan Revenue [Member]
Operating Revenues
Revenue from Contract with Customer, Excluding Assessed Tax	146	120	433	332
Mileage plan other revenue [Member] | Air Group Adjusted [Member]
Operating Revenues
Revenue from Contract with Customer, Excluding Assessed Tax	146	120	433	332
Mileage plan other revenue [Member] | Alaska Mainline [Member]
Operating Revenues
Revenue from Contract with Customer, Excluding Assessed Tax	133	105	392	287
Mileage plan other revenue [Member] | Alaska Regional [Member]
Operating Revenues
Revenue from Contract with Customer, Excluding Assessed Tax	13	15	41	45
Mileage plan other revenue [Member] | Horizon [Member]
Operating Revenues
Revenue from Contract with Customer, Excluding Assessed Tax	0	0	0	0
Mileage plan other revenue [Member] | Consolidating and Other [Member]
Operating Revenues
Revenue from Contract with Customer, Excluding Assessed Tax	0	0	0	0
Mileage plan other revenue [Member] | Special Charges [Member]
Operating Revenues
Revenue from Contract with Customer, Excluding Assessed Tax	0	0	0	0
Cargo and Freight [Member]
Operating Revenues
Revenue from Contract with Customer, Excluding Assessed Tax	67	59	190	160
Cargo and Freight [Member] | Air Group Adjusted [Member]
Operating Revenues
Revenue from Contract with Customer, Excluding Assessed Tax	67	59	190	160
Cargo and Freight [Member] | Alaska Mainline [Member]
Operating Revenues
Revenue from Contract with Customer, Excluding Assessed Tax	65	58	186	157
Cargo and Freight [Member] | Alaska Regional [Member]
Operating Revenues
Revenue from Contract with Customer, Excluding Assessed Tax	0	0	0	0
Cargo and Freight [Member] | Horizon [Member]
Operating Revenues
Revenue from Contract with Customer, Excluding Assessed Tax	0	0	0	0
Cargo and Freight [Member] | Consolidating and Other [Member]
Operating Revenues
Revenue from Contract with Customer, Excluding Assessed Tax	2	1	4	3
Cargo and Freight [Member] | Special Charges [Member]
Operating Revenues
Revenue from Contract with Customer, Excluding Assessed Tax	$ 0	$ 0	$ 0	$ 0