GENERAL AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Policies)	9 Months Ended
Sep. 30, 2017
Accounting Policies [Abstract]
Organization and Basis of Presentation	Organization and Basis of Presentation The condensed consolidated financial statements include the accounts of Air Group, and its primary subsidiaries, Alaska, Horizon, McGee Air Services and, starting December 14, 2016, Virgin America. The Company conducts substantially all of its operations through these subsidiaries. All significant intercompany balances and transactions have been eliminated. These financial statements have been prepared in accordance with accounting principles generally accepted in the United States ("GAAP") for interim financial information. Consistent with these requirements, this Form 10-Q does not include all the information required by GAAP for complete financial statements. It should be read in conjunction with the consolidated financial statements and accompanying notes in the Form 10-K for the year ended December 31, 2016. In the opinion of management, all adjustments have been made that are necessary to fairly present the Company’s financial position as of September 30, 2017 and the results of operations for the three and nine months ended September 30, 2017 and 2016. Such adjustments were of a normal recurring nature. In preparing these statements, the Company is required to make estimates and assumptions that affect the reported amounts of assets and liabilities and the disclosure of contingent liabilities, as well as the reported amounts of revenues and expenses. Due to seasonal variations in the demand for air travel, the volatility of aircraft fuel prices, changes in global economic conditions, changes in the competitive environment and other factors, operating results for the three and nine months ended September 30, 2017 are not necessarily indicative of operating results for the entire year.
Recently Issued Accounting Pronouncements	Recently Issued Accounting Pronouncements In May 2014, the Financial Accounting Standards Board ("FASB") issued Accounting Standards Update ("ASU") 2014-09, "Revenue from Contracts with Customers" (Topic 606), which requires an entity to recognize the amount of revenue to which it expects to be entitled for the transfer of promised goods or services to customers. This comprehensive new standard will replace most existing revenue recognition guidance in U.S. GAAP when it becomes effective. In March 2016, the FASB issued ASU 2016-08, "Revenue from Contracts with Customers (Topic 606), Principal versus Agent Considerations" to clarify the guidance on determining whether the Company is considered the principal or the agent in a revenue transaction where a third party is providing goods or services to a customer. Entities are permitted to use either a full retrospective or cumulative effect transition method, and are required to adopt all parts of the new revenue standard using the same transition method. The new standard is effective for the Company on January 1, 2018. At this time, the Company believes the most significant impact to the financial statements will be to Mileage Plan™ revenues and liabilities. The Company currently uses the incremental cost approach for miles earned through travel. As this approach will be eliminated with the standard, the Company will be required to allocate a portion of the ticket price through a relative selling price model and defer revenue recognition until the ticket is flown or unused mileage credits expire. Additionally, unused companion certificates that were previously recognized at expiration will be subject to advanced breakage under the new standard. The Company estimates a net increase to Mileage Plan deferred revenues of approximately $340 million to $380 million at the time of adoption. The allocated value to miles earned through travel will offset passenger revenue during the period they are issued, rather than recorded using the incremental cost approach. As the program is growing significantly, the Company expects revenue recognized under Topic 606 will be less on an annual basis than current accounting practice. The adoption of the new standard is also expected to result in a change in income statement classification of the majority of ancillary revenues from Other revenue to Passenger revenue. This will affect common industry metrics, such as PRASM and RASM. Certain commission revenue from interline arrangements that were previously offset against related expense will now be classified as Other revenue, which will impact RASM and CASM. Unused ticket revenue that was previously recorded at the time of expiration will now be recorded at the original departure date if that ticket has not been changed or refunded prior to that date, based on estimates of expected expiration. This concept is referred to as ticket breakage. The Company estimates the change in ticket breakage methodology will not have a significant impact on the statements of operations, but will decrease air traffic liability by approximately $70 million to $80 million. The Company continues to evaluate and model the full impact of the standard and will apply the full retrospective transition method. The overall impact to equity as of the beginning of the retroactive reporting period, including the changes discussed above, as well as other less material changes, is expected to be between $160 million and $190 million. In February 2016, the FASB issued ASU 2016-02, "Leases" (Topic 842), which requires lessees to recognize assets and liabilities for leases currently classified as operating leases. Under the new standard, a lessee will recognize a liability on the balance sheet representing the lease payments owed, and a right-of-use-asset representing its right to use the underlying asset for the lease term. For leases with a term of 12 months or less, a lessee is permitted to make an accounting policy election not to recognize lease assets and lease liabilities. At this time, the Company believes the most significant impact to the financial statements will relate to the recording of a right-of-use asset associated with leased aircraft. Other leases, including airports and real estate, equipment, software and other miscellaneous leases continue to be assessed for impact of the ASU. The new standard is effective for the Company on January 1, 2019. Early adoption of the standard is permitted. The Company has determined that it will not early adopt the standard. In March 2016, the FASB issued ASU 2016-09, "Compensation—Stock Compensation" (Topic 718), which simplifies several aspects of accounting for employee share-based payment awards, including the accounting for income taxes, forfeitures and statutory tax withholding requirements, as well as classification in the statement of cash flows. The ASU was adopted prospectively as of January 1, 2017. Prior periods have not been adjusted. The adoption of the standard did not have a material impact on the Company's statements of operations or financial position. In January 2017, the FASB issued ASU 2017-04, "Intangibles—Goodwill and Other" (Topic 350), which eliminates step 2 from the goodwill impairment test. Step 2 measures a goodwill impairment loss by comparing the implied fair value of a reporting unit’s goodwill with the carrying amount of that goodwill. The ASU is effective for the Company beginning January 1, 2019. Early adoption of the standard is permitted. Beginning in fiscal 2017, the Company will be required to perform an impairment test for goodwill arising from its acquisition of Virgin America and has adopted the standard effective January 1, 2017. In March 2017, the FASB issued ASU 2017-07, "Compensation—Retirement Benefits" (Topic 715), which will require the Company to present the service cost component of net periodic benefit cost as Wages and benefits in the statements of operations. All other components of net periodic benefit cost will be required to be presented in Nonoperating income (expense) in the statements of operations. These components will not be eligible for capitalization in assets. The ASU is effective for the Company beginning January 1, 2018. Changes to the statements of operations under the ASU are applicable retrospectively. The adoption of this standard will have no impact on Income before income tax or Net income for the periods subject to retrospective reclassification. See Note 6 for the current components of the Company's net periodic benefit costs.

Recently Issued Accounting Pronouncements

In May 2014, the Financial Accounting Standards Board ("FASB") issued Accounting Standards Update ("ASU") 2014-09, "Revenue from Contracts with Customers" (Topic 606), which requires an entity to recognize the amount of revenue to which it expects to be entitled for the transfer of promised goods or services to customers. This comprehensive new standard will replace most existing revenue recognition guidance in U.S. GAAP when it becomes effective. In March 2016, the FASB issued ASU 2016-08, "Revenue from Contracts with Customers (Topic 606), Principal versus Agent Considerations" to clarify the guidance on determining whether the Company is considered the principal or the agent in a revenue transaction where a third party is providing goods or services to a customer. Entities are permitted to use either a full retrospective or cumulative effect transition method, and are required to adopt all parts of the new revenue standard using the same transition method. The new standard is effective for the Company on January 1, 2018.

At this time, the Company believes the most significant impact to the financial statements will be to Mileage Plan™ revenues and liabilities. The Company currently uses the incremental cost approach for miles earned through travel. As this approach will be eliminated with the standard, the Company will be required to allocate a portion of the ticket price through a relative selling price model and defer revenue recognition until the ticket is flown or unused mileage credits expire. Additionally, unused companion certificates that were previously recognized at expiration will be subject to advanced breakage under the new standard. The Company estimates a net increase to Mileage Plan deferred revenues of approximately $340 million to $380 million at the time of adoption. The allocated value to miles earned through travel will offset passenger revenue during the period they are issued, rather than recorded using the incremental cost approach. As the program is growing significantly, the Company expects revenue recognized under Topic 606 will be less on an annual basis than current accounting practice.

The adoption of the new standard is also expected to result in a change in income statement classification of the majority of ancillary revenues from Other revenue to Passenger revenue. This will affect common industry metrics, such as PRASM and RASM. Certain commission revenue from interline arrangements that were previously offset against related expense will now be classified as Other revenue, which will impact RASM and CASM. Unused ticket revenue that was previously recorded at the time of expiration will now be recorded at the original departure date if that ticket has not been changed or refunded prior to that date, based on estimates of expected expiration. This concept is referred to as ticket breakage. The Company estimates the change in ticket breakage methodology will not have a significant impact on the statements of operations, but will decrease air traffic liability by approximately $70 million to $80 million.

The Company continues to evaluate and model the full impact of the standard and will apply the full retrospective transition method. The overall impact to equity as of the beginning of the retroactive reporting period, including the changes discussed above, as well as other less material changes, is expected to be between $160 million and $190 million.

In February 2016, the FASB issued ASU 2016-02, "Leases" (Topic 842), which requires lessees to recognize assets and liabilities for leases currently classified as operating leases. Under the new standard, a lessee will recognize a liability on the balance sheet representing the lease payments owed, and a right-of-use-asset representing its right to use the underlying asset for the lease term. For leases with a term of 12 months or less, a lessee is permitted to make an accounting policy election not to recognize lease assets and lease liabilities. At this time, the Company believes the most significant impact to the financial statements will relate to the recording of a right-of-use asset associated with leased aircraft. Other leases, including airports and real estate, equipment, software and other miscellaneous leases continue to be assessed for impact of the ASU. The new standard is effective for the Company on January 1, 2019. Early adoption of the standard is permitted. The Company has determined that it will not early adopt the standard.

In March 2016, the FASB issued ASU 2016-09, "Compensation—Stock Compensation" (Topic 718), which simplifies several aspects of accounting for employee share-based payment awards, including the accounting for income taxes, forfeitures and statutory tax withholding requirements, as well as classification in the statement of cash flows. The ASU was adopted prospectively as of January 1, 2017. Prior periods have not been adjusted. The adoption of the standard did not have a material impact on the Company's statements of operations or financial position.

In January 2017, the FASB issued ASU 2017-04, "Intangibles—Goodwill and Other" (Topic 350), which eliminates step 2 from the goodwill impairment test. Step 2 measures a goodwill impairment loss by comparing the implied fair value of a reporting unit’s goodwill with the carrying amount of that goodwill. The ASU is effective for the Company beginning January 1, 2019. Early adoption of the standard is permitted. Beginning in fiscal 2017, the Company will be required to perform an impairment test for goodwill arising from its acquisition of Virgin America and has adopted the standard effective January 1, 2017.

In March 2017, the FASB issued ASU 2017-07, "Compensation—Retirement Benefits" (Topic 715), which will require the Company to present the service cost component of net periodic benefit cost as Wages and benefits in the statements of operations. All other components of net periodic benefit cost will be required to be presented in Nonoperating income (expense) in the statements of operations. These components will not be eligible for capitalization in assets. The ASU is effective for the Company beginning January 1, 2018. Changes to the statements of operations under the ASU are applicable retrospectively. The adoption of this standard will have no impact on Income before income tax or Net income for the periods subject to retrospective reclassification. See Note 6 for the current components of the Company's net periodic benefit costs.