INCOME TAXES - DEFERRED TAX ASSETS AND LIABILITIES (DETAILS) (USD $) In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Income Tax Disclosure [Abstract]
Excess of tax over book depreciation	$ 1,042	$ 919
Other—net	22us-gaap_DeferredTaxLiabilitiesOther	21us-gaap_DeferredTaxLiabilitiesOther
Gross deferred tax liabilities	1,064us-gaap_DeferredTaxLiabilities	940us-gaap_DeferredTaxLiabilities
Mileage Plan	(206)alk_DeferredTaxAssetsMileagePlan	(185)alk_DeferredTaxAssetsMileagePlan
Inventory obsolescence	(20)us-gaap_DeferredTaxAssetsInventory	(18)us-gaap_DeferredTaxAssetsInventory
Deferred gains	(10)us-gaap_DeferredTaxAssetsDeferredIncome	(12)us-gaap_DeferredTaxAssetsDeferredIncome
Employee benefits	(166)	(85)
Fuel hedge contracts	(5)	(14)
Other—net	(24)us-gaap_DeferredTaxAssetsOther	(30)us-gaap_DeferredTaxAssetsOther
Gross deferred tax assets	431us-gaap_DeferredTaxAssetsGross	344us-gaap_DeferredTaxAssetsGross
Net deferred tax liabilities	633us-gaap_DeferredTaxAssetsLiabilitiesNet	596us-gaap_DeferredTaxAssetsLiabilitiesNet
Current deferred tax asset	(117)	(113)
Noncurrent deferred tax liability	$ 750	$ 709

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Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences from deferred income.

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Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences and carryforwards.

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Amount after allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences and carryforwards, net of deferred tax liability attributable to taxable temporary differences expected to be realized or consumed within one year or operating cycle, if longer.

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Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences from compensation and benefits costs.

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Amount of deferred tax liability attributable to taxable temporary differences from property, plant, and equipment.

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