OPERATING SEGMENT INFORMATION (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Operating Revenues
Revenue from Contract with Customer, Excluding Assessed Tax	$ 2,196	$ 1,681
Operating expenses
Operating Expenses, Excluding Fuel	1,717	1,536
Economic fuel	665	347
Total Operating Expenses	2,382	1,883
Nonoperating Income (Expense)
Interest income	17	7
Interest expense	(28)	(27)
Interest capitalized	7	2
Other—net	(9)	14
Nonoperating Income (Expense)	(13)	(4)
Costs and Expenses, Total	$ 2,382	$ 1,883
Pretax Margin, Adjusted	(5.20%)	(14.20%)
Pretax Margin, GAAP	(9.10%)	(12.30%)
Mileage Plan Revenue [Member]
Operating Revenues
Revenue from Contract with Customer, Excluding Assessed Tax	$ 386	$ 300
Air Group Adjusted [Member]
Operating Revenues
Revenue from Contract with Customer, Excluding Assessed Tax	2,196	1,681
Operating expenses
Operating Expenses, Excluding Fuel	1,653	1,461
Economic fuel	645	454
Total Operating Expenses	2,298	1,915
Nonoperating Income (Expense)
Nonoperating Income (Expense)	(13)	(4)
Income (loss) before income tax	(115)	(238)
Alaska Mainline [Member]
Operating Revenues
Revenue from Contract with Customer, Excluding Assessed Tax	1,890	1,400
Operating expenses
Operating Expenses, Excluding Fuel	1,390	1,194
Economic fuel	561	381
Total Operating Expenses	1,951	1,575
Nonoperating Income (Expense)
Nonoperating Income (Expense)	(6)	1
Income (loss) before income tax	(67)	(174)
Alaska Regional [Member]
Operating Revenues
Revenue from Contract with Customer, Excluding Assessed Tax	305	280
Operating expenses
Operating Expenses, Excluding Fuel	256	262
Economic fuel	85	73
Total Operating Expenses	341	335
Nonoperating Income (Expense)
Nonoperating Income (Expense)	0	0
Income (loss) before income tax	(36)	(55)
Horizon [Member]
Operating Revenues
Revenue from Contract with Customer, Excluding Assessed Tax	78	94
Operating expenses
Operating Expenses, Excluding Fuel	84	99
Economic fuel	0	0
Total Operating Expenses	84	99
Nonoperating Income (Expense)
Nonoperating Income (Expense)	(8)	(5)
Income (loss) before income tax	(14)	(10)
Consolidating and Other [Member]
Operating Revenues
Revenue from Contract with Customer, Excluding Assessed Tax	(77)	(93)
Operating expenses
Operating Expenses, Excluding Fuel	(77)	(94)
Economic fuel	(1)	0
Total Operating Expenses	(78)	(94)
Nonoperating Income (Expense)
Nonoperating Income (Expense)	1	0
Income (loss) before income tax	2	1
Special Charges [Member]
Operating Revenues
Revenue from Contract with Customer, Excluding Assessed Tax	0	0
Operating expenses
Operating Expenses, Excluding Fuel	64	75
Economic fuel	20	(107)
Total Operating Expenses	84	(32)
Nonoperating Income (Expense)
Nonoperating Income (Expense)	0	0
Income (loss) before income tax	(84)	32
Passenger [Member]
Operating Revenues
Revenue from Contract with Customer, Excluding Assessed Tax	1,984	1,511
Passenger [Member] | Air Group Adjusted [Member]
Operating Revenues
Revenue from Contract with Customer, Excluding Assessed Tax	1,984	1,511
Passenger [Member] | Alaska Mainline [Member]
Operating Revenues
Revenue from Contract with Customer, Excluding Assessed Tax	1,690	1,243
Passenger [Member] | Alaska Regional [Member]
Operating Revenues
Revenue from Contract with Customer, Excluding Assessed Tax	294	268
Passenger [Member] | Horizon [Member]
Operating Revenues
Revenue from Contract with Customer, Excluding Assessed Tax	0	0
Passenger [Member] | Consolidating and Other [Member]
Operating Revenues
Revenue from Contract with Customer, Excluding Assessed Tax	0	0
Passenger [Member] | Special Charges [Member]
Operating Revenues
Revenue from Contract with Customer, Excluding Assessed Tax	0	0
Capacity Purchase Agreements [Member]
Operating Revenues
Revenue from Contract with Customer, Excluding Assessed Tax	0	0
Capacity Purchase Agreements [Member] | Air Group Adjusted [Member]
Operating Revenues
Revenue from Contract with Customer, Excluding Assessed Tax	0	0
Capacity Purchase Agreements [Member] | Alaska Mainline [Member]
Operating Revenues
Revenue from Contract with Customer, Excluding Assessed Tax	0	0
Capacity Purchase Agreements [Member] | Alaska Regional [Member]
Operating Revenues
Revenue from Contract with Customer, Excluding Assessed Tax	0	0
Capacity Purchase Agreements [Member] | Horizon [Member]
Operating Revenues
Revenue from Contract with Customer, Excluding Assessed Tax	78	94
Capacity Purchase Agreements [Member] | Consolidating and Other [Member]
Operating Revenues
Revenue from Contract with Customer, Excluding Assessed Tax	(78)	(94)
Capacity Purchase Agreements [Member] | Special Charges [Member]
Operating Revenues
Revenue from Contract with Customer, Excluding Assessed Tax	0	0
Mileage plan other revenue [Member]
Operating Revenues
Revenue from Contract with Customer, Excluding Assessed Tax	154	112
Mileage plan other revenue [Member] | Mileage Plan Revenue [Member]
Operating Revenues
Revenue from Contract with Customer, Excluding Assessed Tax	154	112
Mileage plan other revenue [Member] | Air Group Adjusted [Member]
Operating Revenues
Revenue from Contract with Customer, Excluding Assessed Tax	154	112
Mileage plan other revenue [Member] | Alaska Mainline [Member]
Operating Revenues
Revenue from Contract with Customer, Excluding Assessed Tax	143	100
Mileage plan other revenue [Member] | Alaska Regional [Member]
Operating Revenues
Revenue from Contract with Customer, Excluding Assessed Tax	11	12
Mileage plan other revenue [Member] | Horizon [Member]
Operating Revenues
Revenue from Contract with Customer, Excluding Assessed Tax	0	0
Mileage plan other revenue [Member] | Consolidating and Other [Member]
Operating Revenues
Revenue from Contract with Customer, Excluding Assessed Tax	0	0
Mileage plan other revenue [Member] | Special Charges [Member]
Operating Revenues
Revenue from Contract with Customer, Excluding Assessed Tax	0	0
Cargo and Freight [Member]
Operating Revenues
Revenue from Contract with Customer, Excluding Assessed Tax	58	58
Cargo and Freight [Member] | Air Group Adjusted [Member]
Operating Revenues
Revenue from Contract with Customer, Excluding Assessed Tax	58	58
Cargo and Freight [Member] | Alaska Mainline [Member]
Operating Revenues
Revenue from Contract with Customer, Excluding Assessed Tax	57	57
Cargo and Freight [Member] | Alaska Regional [Member]
Operating Revenues
Revenue from Contract with Customer, Excluding Assessed Tax	0	0
Cargo and Freight [Member] | Horizon [Member]
Operating Revenues
Revenue from Contract with Customer, Excluding Assessed Tax	0	0
Cargo and Freight [Member] | Consolidating and Other [Member]
Operating Revenues
Revenue from Contract with Customer, Excluding Assessed Tax	1	1
Cargo and Freight [Member] | Special Charges [Member]
Operating Revenues
Revenue from Contract with Customer, Excluding Assessed Tax	$ 0	$ 0