EMPLOYEE BENEFIT PLANS  - Narrative (Details)	12 Months Ended
	Dec. 31, 2024 USD ($) plan	Dec. 31, 2023 USD ($)	Dec. 31, 2022 USD ($)
Defined Benefit Plan Disclosure [Line Items]
Number of qualified defined benefit plans | plan	5
Number of defined contribution plans | plan	12
Expected required contributions, next fiscal year	$ 52,000,000
Total expense for the defined-contribution plans	256,000,000	$ 203,000,000	$ 160,000,000
Variable incentive pay	$ 358,000,000	200,000,000	257,000,000
Operational Performance Rewards Program entitles all Air Group employees to maximum quarterly payouts (in dollars per quarter)	450
Alaska Air Group
Defined Benefit Plan Disclosure [Line Items]
Number of qualified defined benefit plans | plan	4
Hawaiian Holdings, Inc.
Defined Benefit Plan Disclosure [Line Items]
Number of qualified defined benefit plans | plan	1
Number defined benefit postretirement and medical life insurance plans | plan	4
Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Accumulated benefit obligation	$ 2,400,000,000	2,100,000,000
Benefit obligation	2,462,000,000	2,183,000,000	$ 2,079,000,000
Postretirement Medical Benefits | Alaska Air Group
Defined Benefit Plan Disclosure [Line Items]
Benefit obligation	93,000,000	98,000,000
Postretirement Medical Benefits | Hawaiian Holdings, Inc.
Defined Benefit Plan Disclosure [Line Items]
Benefit obligation	159,000,000
Postretirement Health Coverage
Defined Benefit Plan Disclosure [Line Items]
Total liability net of a prefunded trust account	86,000,000	72,000,000
Prefunded trust account	$ 13,000,000	$ 10,000,000