| Cover | Oct. 14, 2021 |
| Cover [Abstract] | |
| Document Type | 8-K |
| Document Period End Date | Oct. 14, 2021 |
| Entity Registrant Name | ALASKA AIR GROUP, INC. |
| Entity Central Index Key | 0000766421 |
| Amendment Flag | false |
| Entity Incorporation, State or Country Code | DE |
| Entity File Number | 1-8957 |
| Entity Tax Identification Number | 91-1292054 |
| Title of 12(b) Security | Common stock, $0.01 par value |
| Security Exchange Name | NYSE |
| Trading Symbol | ALK |
| Entity Address, Address Line One | 19300 International Boulevard |
| Entity Address, City or Town | Seattle |
| Entity Address, State or Province | WA |
| Entity Address, Postal Zip Code | 98188 |
| City Area Code | 206 |
| Local Phone Number | 392-5040 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Entity Emerging Growth Company | false |
