Business Combinations [Abstract] Schedule of Business Acquisitions, by Acquisition [Table] Schedule of Business Acquisitions, by Acquisition [Table] Business Acquisition [Axis] Business Acquisition [Axis] Business Acquisition, Acquiree [Domain] Business Acquisition, Acquiree [Domain] Virgin America Inc. Virgin America Inc. [Member] Virgin America Inc. [Member] Business Acquisition [Line Items] Business Acquisition [Line Items] Cash and cash equivalents Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Cash and Equivalents Receivables Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets, Receivables Prepaid expenses and other current assets Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets, Prepaid Expense and Other Assets Property and equipment Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Property, Plant, and Equipment Intangible assets Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Finite-Lived Intangibles Goodwill Goodwill Other assets Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Other Noncurrent Assets Total assets Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Assets Acquired Including Goodwill Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Assets Acquired Including Goodwill Accounts payable Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Liabilities, Accounts Payable Accrued wages, vacation and payroll taxes Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Liabilities, Accrued Wages, Vacation and Payroll Taxes Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Liabilities, Accrued Wages, Vacation and Payroll Taxes Air traffic liabilities Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Liabilities, Air Traffic Liabilities Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Liabilities, Air Traffic Liabilities Other accrued liabilities Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Liabilities, Other Current portion of long-term debt Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Liabilities, Long-term Debt Long-term debt, net of current portion Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Noncurrent Liabilities, Long-term Debt Deferred income taxes Business Combination Recognized Identifiable Assets Acquired and Liabilities Assumed, Deferred Tax Assets Deferred revenue Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Noncurrent Liabilities, Deferred Revenue Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Noncurrent Liabilities, Deferred Revenue Other liabilities Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Noncurrent Liabilities, Other Total liabilities Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Liabilities Total purchase price Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Net Fair Value Disclosures [Abstract] FAIR VALUE MEASUREMENTS Fair Value Disclosures [Text Block] Segment Reporting [Abstract] Schedule of Segment Reporting Information, by Segment [Table] Schedule of Segment Reporting Information, by Segment [Table] Statement, Business Segments [Axis] Segments [Axis] Segment [Domain] Segments [Domain] Air Group Adjusted [Member] Air Group Adjusted [Member] Air Group Adjusted [Member] Alaska Airlines [Member] Alaska Airlines [Member] Alaska Airlines [Member] Alaska Mainline [Member] Alaska Mainline [Member] Alaska Mainline [Member] Alaska Regional [Member] Alaska Regional [Member] Alaska Regional [Member] Horizon [Member] Horizon [Member] Horizon Segment [Member] Intersegment Elimination [Member] Intersegment Eliminations [Member] Special Revenue and Charges [Member] Special Revenue and Charges [Member] Segment Reporting Information [Line Items] Segment Reporting Information [Line Items] Number of Operating Segments Number of Operating Segments Capacity purchase arrangements Airline, Capacity Purchase Arrangements, Percent Airline, Capacity Purchase Arrangements, Percent Operating revenues Revenues [Abstract] Passenger, Mainline Passenger Revenue, Mainline Passenger, Regional Passenger Revenue, Regional Total passenger revenue Passenger Revenue CPA revenues Revenue from Related Parties Freight and mail Cargo and Freight Revenue Other - net revenue Other Net and Special Revenue Other Net and Special Revenue Total Operating Revenues Revenue, Net Operating expenses Operating Expenses [Abstract] Operating Expenses, Excluding Fuel Operating Expenses, Excluding Fuel Operating Expenses, Excluding Fuel Economic fuel Fuel Costs Total Operating Expenses Operating Expenses Nonoperating Income (Expense) Nonoperating Income (Expense) [Abstract] Interest income Investment Income, Interest Interest expense Interest Expense Other Other Nonoperating Income Expense Other Other Nonoperating Income Expense Other Nonoperating Income (Expense) Total Nonoperating Income (Expense) Income (loss) before income tax Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Noncontrolling Interest Compensation and Retirement Disclosure [Abstract] Schedule of Defined Benefit Plans Disclosures [Table] Schedule of Defined Benefit Plans Disclosures [Table] Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Axis] Defined Benefit Plans and Other Postretirement Benefit Plans [Axis] Defined Benefit Plans and Other Postretirement Benefit Plans [Domain] Defined Benefit Plan and Other Postretirement Benefit Plan [Domain] Qualified Defined Benefit [Member] Pension Plan [Member] Defined Benefit Plan Disclosure [Line Items] Defined Benefit Plan Disclosure [Line Items] Defined Benefit Plan, Contributions by Employer Defined Benefit Plan, Contributions by Employer Defined Benefit Plan, Net Periodic Benefit Cost [Abstract] Defined Benefit Plan, Net Periodic Benefit Cost [Abstract] Service cost Defined Benefit Plan, Service Cost Interest cost Defined Benefit Plan, Interest Cost Expected return on assets Defined Benefit Plan, Expected Return on Plan Assets Amortization of prior service cost (credit) Defined Benefit Plan, Amortization of Prior Service Cost (Credit) Recognized actuarial loss (gain) Defined Benefit Plan, Amortization of Gains (Losses) Net pension expense Defined Benefit Plan, Net Periodic Benefit Cost Statement of Financial Position [Abstract] ASSETS Assets [Abstract] Current Assets Assets, Current [Abstract] Cash and cash equivalents Cash and Cash Equivalents, at Carrying Value Marketable securities Marketable Securities, Current Total cash and marketable securities Cash, Cash Equivalents, and Short-term Investments Receivables—net Receivables, Net, Current Inventories and supplies—net Inventory, Net Prepaid expenses and other current assets Prepaid Expense and Other Assets, Current Total Current Assets Assets, Current Property and Equipment Property, Plant and Equipment, Net [Abstract] Aircraft and other flight equipment Flight Equipment, Gross Other property and equipment Property, Plant and Equipment, Other, Gross Deposits for future flight equipment Deposits on Flight Equipment Property and Equipment Total Property, Plant and Equipment, Gross Less accumulated depreciation and amortization Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment Total Property and Equipment—Net Property, Plant and Equipment, Net Intangible assets Intangible Assets, Net (Excluding Goodwill) Other noncurrent assets Other Assets, Noncurrent Other Assets Other Assets Total Assets Assets LIABILITIES AND SHAREHOLDERS' EQUITY Liabilities and Equity [Abstract] Current Liabilities Liabilities, Current [Abstract] Accounts payable Accounts Payable, Current Accrued wages, vacation and payroll taxes Employee-related Liabilities, Current Air traffic liability Deferred Air Traffic Revenue, Current Other accrued liabilities Accrued Liabilities, Current Current portion of long-term debt Debt, Current Total Current Liabilities Liabilities, Current Long-Term Debt, Net of Current Portion Long-term Debt, Excluding Current Maturities Other Liabilities and Credits Liabilities, Noncurrent [Abstract] Deferred income taxes Deferred Tax Liabilities, Net, Noncurrent Deferred revenue Deferred Revenue Obligation for pension and postretirement medical benefits Pension and Other Postretirement Defined Benefit Plans, Liabilities, Noncurrent Other liabilities Other Liabilities, Noncurrent Other Liabilities and Credits Totals Liabilities, Noncurrent Commitments and Contingencies Commitments and Contingencies Shareholders' Equity Stockholders' Equity, Number of Shares, Par Value and Other Disclosures [Abstract] Preferred stock, $0.01 par value, Authorized: 5,000,000 shares, none issued or outstanding Preferred Stock, Value, Issued Common stock, $0.01 par value, Authorized: 400,000,000 shares, Issued: 2017 - 129,860,836 shares; 2016 - 129,189,634 shares, Outstanding: 2017 - 123,387,158 shares; 2016 - 123,328,051 shares Common Stock, Value, Issued Capital in excess of par value Additional Paid in Capital, Common Stock Treasury stock (common), at cost: 2017 - 6,473,678 shares; 2016 - 5,861,583 shares Treasury Stock, Value Accumulated other comprehensive loss Accumulated Other Comprehensive Income (Loss), Net of Tax Retained earnings Retained Earnings (Accumulated Deficit) Total Shareholders' Equity Stockholders' Equity Attributable to Parent Total Liabilities and Shareholders' Equity Liabilities and Equity OPERATING SEGMENT INFORMATION Segment Reporting Disclosure [Text Block] Equity [Abstract] Cash dividend declared per share (usd per share) Common Stock, Dividends, Per Share, Declared Payments of Dividends Payments of Dividends Fair Value, Assets Measured on Recurring Basis Fair Value, Assets Measured on Recurring Basis [Table Text Block] Fair Value, Liabilities Measured on Recurring Basis Fair Value, Liabilities Measured on Recurring Basis [Table Text Block] Activity for Marketable Securities Available-for-sale Securities [Table Text Block] Investments Classified by Contractual Maturity Date Investments Classified by Contractual Maturity Date [Table Text Block] Fair Value, by Balance Sheet Grouping Fair Value, by Balance Sheet Grouping [Table Text Block] Accounting Policies [Abstract] Organization and Basis of Presentation Basis of Accounting, Policy [Policy Text Block] Recently Issued Accounting Pronouncements New Accounting Pronouncements, Policy [Policy Text Block] Schedule of Segment Reporting Information, by Segment Schedule of Segment Reporting Information, by Segment [Table Text Block] Document and Entity Information [Abstract] Document and Entity Information [Abstract] Document Type Document Type Amendment Flag Amendment Flag Document Period End Date Document Period End Date Document Fiscal Year Focus Document Fiscal Year Focus Document Fiscal Period Focus Document Fiscal Period Focus Entity Registrant Name Entity Registrant Name Entity Central Index Key Entity Central Index Key Current Fiscal Year End Date Current Fiscal Year End Date Entity Filer Category Entity Filer Category Entity Common Stock, Shares Outstanding Entity Common Stock, Shares Outstanding Income Statement Location [Axis] Income Statement Location [Axis] Income Statement Location [Domain] Income Statement Location [Domain] Class of Stock [Axis] Class of Stock [Axis] Class of Stock [Domain] Class of Stock [Domain] Fair Value of Assets Acquired and Liabilities Assumed Schedule of Recognized Identified Assets Acquired and Liabilities Assumed [Table Text Block] Statement of Comprehensive Income [Abstract] Net Income Net Income (Loss) Attributable to Parent Other Comprehensive Income (Loss): Other Comprehensive Income (Loss), Tax [Abstract] Related to marketable securities: Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, Net of Tax [Abstract] Unrealized holding gain (loss) arising during the period Other Comprehensive Income (Loss), Unrealized Holding Gain (Loss) on Securities Arising During Period, before Tax Reclassification of (gain) loss into Other—net nonoperating income (expense) Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI for Sale of Securities, before Tax Income tax effect Other Comprehensive Income (Loss), Available-for-sale Securities, Tax Total Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, Net of Tax Related to employee benefit plans: Other Comprehensive (Income) Loss, Pension and Other Postretirement Benefit Plans, Adjustment, Net of Tax [Abstract] Reclassification of net pension expense into Wages and benefits Other Comprehensive (Income) Loss, Pension and Other Postretirement Benefit Plans, Adjustment, before Tax Income tax effect Other Comprehensive Income (Loss), Tax Total Other Comprehensive (Income) Loss, Pension and Other Postretirement Benefit Plans, Adjustment, Net of Tax Related to interest rate derivative instruments: Derivative Instruments and Hedges, Assets [Abstract] Unrealized holding gain (loss) arising during the period Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, before Tax Reclassification of (gain) loss into Aircraft rent Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI on Derivatives, before Tax Income tax effect Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Tax Total Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Net of Tax Other Comprehensive Income Other Comprehensive Income (Loss), Net of Tax Comprehensive Income Comprehensive Income (Loss), Net of Tax, Attributable to Parent FREQUENT FLYER PROGRAMS [Abstract] FREQUENT FLYER PROGRAMS [Abstract] FREQUENT FLYER PROGRAMS LIABILITIES Frequent Flyer Programs Liabilities [Table Text Block] Frequent Flyer Programs Liabilities [Table Text Block] FREQUENT FLYER PROGRAMS REVENUE Frequent Flyer Programs Revenue [Table Text Block] Frequent Flyer Programs Revenue [Table Text Block] Percentage of common shares and voting interest acquired Business Acquisition, Percentage of Voting Interests Acquired Consideration paid (usd per share) Business Acquisition, Share Price Cash consideration Payments to Acquire Businesses, Gross Number of daily departures Number of Daily Departures Number of Daily Departures Merger-related costs Business Combination, Acquisition Related Costs Schedule of Net Benefit Costs Schedule of Net Benefit Costs [Table Text Block] Debt Disclosure [Abstract] Schedule of Long-term Debt Instruments [Table] Schedule of Long-term Debt Instruments [Table] Debt Instrument [Axis] Debt Instrument [Axis] Debt Instrument, Name [Domain] Debt Instrument, Name [Domain] Fixed rate notes payable due through 2028 [Member] Fixed rate notes payable due through 2028 [Member] Fixed rate notes payable due through 2028 [Member] Variable rate notes payable due through 2028 [Member] Variable rate notes payable due through 2028 [Member] Variable rate notes payable due through 2028 [Member] Debt Instrument [Line Items] Debt Instrument [Line Items] Line of Credit Facility, Expiration Date Line of Credit Facility, Expiration Date Repayments of Long-term Debt Repayments of Long-term Debt Total Long-term Debt Debt Issuance Costs, Net Debt Issuance Costs, Net Less current portion Long-term Debt, Current Maturities Long-term debt, less current portion Weighted-average fixed-interest rate Long-term Debt, Percentage Bearing Fixed Interest, Percentage Rate Weighted-average variable-interest rate Long-term Debt, Percentage Bearing Variable Interest, Percentage Rate Commitments and Contingencies Disclosure [Abstract] Schedule of Future Minimum Rental Payments for Operating Leases and Unrecorded Unconditional Purchase Obligtaions Schedule of Future Minimum Rental Payments for Operating Leases and Unrecorded Unconditional Purchase Obligations [Table Text Block] Schedule of Future Minimum Rental Payments for Operating Leases and Unrecorded Unconditional Purchase Obligtaions [Table Text Block] Schedule of Long-term Debt Instruments Schedule of Long-term Debt Instruments [Table Text Block] Schedule of Maturities of Long-term Debt Schedule of Maturities of Long-term Debt [Table Text Block] Subsequent Events [Abstract] Subsequent Event [Table] Subsequent Event [Table] Subsequent Event Type [Axis] Subsequent Event Type [Axis] Subsequent Event Type [Domain] Subsequent Event Type [Domain] Subsequent Event [Line Items] Subsequent Event [Line Items] Subsequent Events [Text Block] Subsequent Events [Text Block] Long-term Debt, Fiscal Year Maturity [Abstract] Long-term Debt, Fiscal Year Maturity [Abstract] Remainder of 2017 Long-term Debt, Maturities, Repayments of Principal, Remainder of Fiscal Year 2018 Long-term Debt, Maturities, Repayments of Principal in Year Two 2019 Long-term Debt, Maturities, Repayments of Principal in Year Three 2020 Long-term Debt, Maturities, Repayments of Principal in Year Four 2021 Long-term Debt, Maturities, Repayments of Principal in Year Five Thereafter Long-term Debt, Maturities, Repayments of Principal after Year Five Total Long-term Debt, Gross Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Table] Fair Value Measurements, Recurring and Nonrecurring [Table] Major Types of Debt and Equity Securities [Axis] Major Types of Debt and Equity Securities [Domain] U.S. government and agency securities [Member] US Treasury and Government [Member] Foreign government bonds [Member] Foreign Government Debt Securities [Member] Asset-backed securities [Member] Asset-backed Securities, Securitized Loans and Receivables [Member] Mortgage-backed securities [Member] Collateralized Mortgage Backed Securities [Member] Corporate notes and bonds [Member] Corporate Debt Securities [Member] Municipal securities [Member] US States and Political Subdivisions Debt Securities [Member] Derivative Instrument [Axis] Derivative Contract [Domain] Fuel hedge contracts [Member] Commodity Contract [Member] Interest rate swaps agreements [Member] Interest Rate Swap [Member] Fair Value, Hierarchy [Axis] Fair Value, Hierarchy [Axis] Fair Value, Measurements, Fair Value Hierarchy [Domain] Fair Value Hierarchy [Domain] Level 1 [Member] Fair Value, Inputs, Level 1 [Member] Level 2 [Member] Fair Value, Inputs, Level 2 [Member] Fair Value by Measurement Frequency [Axis] Measurement Frequency [Axis] Fair Value, Measurement Frequency [Domain] Fair Value, Measurement Frequency [Domain] Recurring [Member] Fair Value, Measurements, Recurring [Member] Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] Marketable securities Available-for-sale Securities Derivative instruments, assets Derivative Asset Assets, Fair Value Disclosure, Recurring Assets, Fair Value Disclosure, Recurring Derivative instruments, liabilities Derivative Liability Liabilities, Fair Value Disclosure, Recurring Liabilities, Fair Value Disclosure, Recurring Cost Basis Available-for-sale Securities, Debt Maturities, Amortized Cost Basis, Rolling Maturity [Abstract] Due in one year or less Available-for-sale Securities, Debt Maturities, Next Rolling Twelve Months, Amortized Cost Basis Due after one year through five years Available-for-sale Securities, Debt Maturities, Rolling Year Two Through Five, Amortized Cost Basis Due after five years through 10 years Available-for-sale Securities, Debt Maturities, Rolling Year Six Through Ten, Amortized Cost Basis Due after 10 years Available-for-sale Securities, Debt Maturities, Rolling after Year Ten, Amortized Cost Basis Total Available-for-sale Securities, Amortized Cost Basis Fair Value Available-for-sale Securities, Debt Maturities, Fair Value, Rolling Maturity [Abstract] Due in one year or less Available-for-sale Securities, Debt Maturities, Next Rolling Twelve Months, Fair Value Due after one year through five years Available-for-sale Securities, Debt Maturities, Rolling Year Two Through Five, Fair Value Due after five years through 10 years Available-for-sale Securities, Debt Maturities, Rolling Year Six Through Ten, Fair Value Due after 10 years Available-for-sale Securities, Debt Maturities, Rolling after Year Ten, Fair Value Total Available-for-sale Securities, Current Line of Credit Facility [Table] Line of Credit Facility [Table] Credit Facility 1 [Member] Credit Facility 1 [Member] Credit Facility 1 [Member] Credit Facility 2 [Member] Credit Facility 2 [Member] Credit Facility 2 [Member] Credit Facility 3 [Member] Credit Facility 3 [Member] Credit Facility 3 [Member] Credit Facilities 1 and 2 [Member] Credit Facilities 1 and 2 [Member] Credit Facilities 1 and 2 [Member] Line of Credit Facility [Axis] Lender Name [Axis] Line of Credit Facility, Lender [Domain] Line of Credit Facility, Lender [Domain] Secured by aircraft [Member] Secured by aircraft [Member] Secured by aircraft [Member] Secured by certain accounts receivable, spare engines, spare parts and ground service equipment [Member] Secured by other [Member] Secured by other [Member] Line of Credit Facility [Line Items] Line of Credit Facility [Line Items] Line of Credit Facility, Number of Credit Facilities Line of Credit Facility, Number of Credit Facilities Line of Credit Facility, Number of Credit Facilities Line of Credit Facility, Maximum Borrowing Capacity Line of Credit Facility, Maximum Borrowing Capacity Line of Credit Facility, Asset Restrictions Line of Credit Facility, Asset Restrictions, Unrestricted Cash and Marketable Securities Line of Credit Facility, Asset Restrictions, Unrestricted Cash and Marketable Securities GENERAL AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES Significant Accounting Policies [Text Block] EMPLOYEE BENEFIT PLANS Pension and Other Postretirement Benefits Disclosure [Text Block] OPERATING SEGMENT INFORMATION [Abstract] OPERATING SEGMENT INFORMATION [Abstract] Statement [Table] Statement [Table] Parent [Member] Segment Reconciling Items [Member] Statement [Line Items] Statement [Line Items] Total assets Income Statement [Abstract] Operating Revenues Passenger, Mainline Passenger, Regional Other—net Other Revenue, Net Operating Expenses Wages and benefits Labor and Related Expense Variable incentive pay Other Labor-related Expenses Aircraft fuel, including hedging gains and losses Aircraft maintenance Aircraft Maintenance, Materials, and Repairs Aircraft rent Aircraft Rental Landing fees and other rentals Landing Fees and Other Rentals Contracted services Professional and Contract Services Expense Selling expenses Selling Expense Depreciation and amortization Depreciation, Depletion and Amortization Food and beverage service Food and Beverage, Cost of Sales Third-party regional carrier expense Regional Carrier Expense Regional Carrier Expense Special items—merger-related costs Other Other Cost and Expense, Operating Operating Income Operating Income (Loss) Interest expense Interest capitalized Interest Costs Capitalized Adjustment Other—net Other Nonoperating Income (Expense) Income before income tax Income tax expense Income Tax Expense (Benefit) Net Income Basic Earnings Per Share (usd per share) Earnings Per Share, Basic Diluted Earnings Per Share (usd per share) Earnings Per Share, Diluted Shares used for computation: Earnings Per Share [Abstract] Basic shares (shares) Weighted Average Number of Shares Outstanding, Basic Diluted shares (shares) Weighted Average Number of Shares Outstanding, Diluted Proceeds from sales and maturities Available-for-sale Securities, Gross Realized Gains (Losses), Sale Proceeds LONG-TERM DEBT Long-term Debt [Text Block] COMMITMENTS Commitments Disclosure [Text Block] Marketable securities Accumulated Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, Net of Tax Employee benefit plans Accumulated Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Net of Tax Interest rate derivatives Accumulated Other Comprehensive Income (Loss), Cumulative Changes in Net Gain (Loss) from Cash Flow Hedges, Effect Net of Tax Total Stockholders' Equity: Stockholders' Equity Attributable to Parent [Abstract] Preferred Stock, par value (usd per share) Preferred Stock, Par or Stated Value Per Share Preferred stock, shares authorized (shares) Preferred Stock, Shares Authorized Preferred stock, shares issued (shares) Preferred Stock, Shares Issued Preferred stock, shares outstanding (shares) Preferred Stock, Shares Outstanding Common stock, par value (usd per share) Common Stock, Par or Stated Value Per Share Common stock, shares authorized (shares) Common Stock, Shares Authorized Common stock, shares issued (shares) Common Stock, Shares, Issued Common stock, shares outstanding (shares) Common Stock, Shares, Outstanding Treasury Stock, Shares (shares) Treasury Stock, Shares SHAREHOLDERS' EQUITY Stockholders' Equity Note Disclosure [Text Block] Schedule of Stock by Class [Table] Schedule of Stock by Class [Table] Subsequent Event [Member] Subsequent Event [Member] Share Repurchase Program [Axis] Share Repurchase Program [Axis] Share Repurchase Program [Domain] Share Repurchase Program [Domain] 2015 1 Billion Repurchase Program [Member] 2015 1 Billion Repurchase Program [Member] 2015 1 Billion Repurchase Program [Member] Class of Stock [Line Items] Class of Stock [Line Items] Stock repurchase program, authorized amount (shares) Stock Repurchase Program, Authorized Amount Stock repurchased during period (shares) Stock Repurchased During Period, Shares Value of stock repurchased during period Stock Repurchased During Period, Value Shares Treasury Stock, Shares, Acquired Amount Treasury Stock, Value, Acquired, Cost Method Fair Value, by Balance Sheet Grouping [Table] Fair Value, by Balance Sheet Grouping [Table] Measurement Basis [Axis] Measurement Basis [Axis] Fair Value Measurement [Domain] Fair Value Measurement [Domain] Portion at Fair Value Measurement [Member] Portion at Fair Value Measurement [Member] Carrying amount [Member] Reported Value Measurement [Member] Fair value [Member] Estimate of Fair Value Measurement [Member] Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] Long-term debt Notes Payable, Fair Value Disclosure Statement of Cash Flows [Abstract] Scenario [Axis] Scenario [Axis] Scenario, Unspecified [Domain] Scenario, Unspecified [Domain] Cash flows from operating activities: Net Cash Provided by (Used in) Operating Activities [Abstract] Adjustments to reconcile net income to net cash provided by operating activities: Adjustments to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities [Abstract] Stock-based compensation and other Share-based Compensation Changes in certain assets and liabilities: Increase (Decrease) in Other Operating Assets and Liabilities, Net [Abstract] Changes in deferred tax provision Increase (Decrease) in Deferred Income Taxes Increase in air traffic liability Increase (Decrease) in Air Traffic Liability Increase in deferred revenue Increase (Decrease) in Deferred Revenue Other—net Other Operating Activities, Cash Flow Statement Net cash provided by operating activities Net Cash Provided by (Used in) Operating Activities Cash flows from investing activities: Net Cash Provided by (Used in) Investing Activities [Abstract] Property and equipment additions: Payments to Acquire Productive Assets [Abstract] Aircraft and aircraft purchase deposits Payments for Flight Equipment Other flight equipment Payments to Acquire Other Productive Assets Other property and equipment Payments to Acquire Other Property, Plant, and Equipment Total property and equipment additions, including capitalized interest Payments to Acquire Property, Plant, and Equipment Purchases of marketable securities Payments to Acquire Marketable Securities Sales and maturities of marketable securities Proceeds from Sale and Maturity of Marketable Securities Other investing activities Payments for (Proceeds from) Other Investing Activities Net cash used in investing activities Net Cash Provided by (Used in) Investing Activities Cash flows from financing activities: Net Cash Provided by (Used in) Financing Activities [Abstract] Proceeds from issuance of debt Proceeds from Issuance of Secured Debt Long-term debt payments Common stock repurchases Payments for Repurchase of Common Stock Dividends paid Other financing activities Proceeds from (Payments for) Other Financing Activities Net cash provided (used) by financing activities Net Cash Provided by (Used in) Financing Activities Net increase (decrease) in cash and cash equivalents Cash and Cash Equivalents, Period Increase (Decrease) Cash and cash equivalents at beginning of year Cash and cash equivalents at end of the period Supplemental disclosure: Supplemental Cash Flow Information [Abstract] Cash paid during the period for: Caid Paid Refunded [Abstract] Caid Paid Refunded [Abstract] Interest (net of amount capitalized) Interest Paid, Net Income taxes Income Taxes Paid, Net Non-cash transactions: Nonmonetary Transactions [Abstract] FREQUENT FLYER PROGRAMS Frequent Flyer Programs Disclosure [Text Block] Frequent Flyer Programs Disclosure [Text Block] New Accounting Pronouncements or Change in Accounting Principle [Table] New Accounting Pronouncements or Change in Accounting Principle [Table] Adjustments for New Accounting Pronouncements [Axis] Adjustments for New Accounting Pronouncements [Axis] Type of Adoption [Domain] Type of Adoption [Domain] Accounting Standards Update 2014-09 [Member] Accounting Standards Update 2014-09 [Member] Range [Axis] Range [Axis] Range [Domain] Range [Domain] Minimum [Member] Minimum [Member] Maximum [Member] Maximum [Member] Scenario, Forecast [Member] Scenario, Forecast [Member] New Accounting Pronouncements or Change in Accounting Principle [Line Items] New Accounting Pronouncements or Change in Accounting Principle [Line Items] Amount of increase to the liability for earned miles Contract with Customer, Liability Contract with Customer, Liability Amount of decrease to air traffic liability Contract with Customer, Air Traffic Liability Contract with Customer, Air Traffic Liability Overall impact on equity Cumulative Effect of New Accounting Principle in Period of Adoption ACQUISITION OF VIRGIN AMERICA INC. Business Combination Disclosure [Text Block] Frequent Flyer Program [Table] Frequent Flyer Program [Table] Frequent Flyer Program [Table] Frequent Flyer Program [Axis] Frequent Flyer Program [Axis] Frequent Flyer Program [Axis] Frequent Flyer Program [Domain] Frequent Flyer Program [Domain] [Domain] for Frequent Flyer Program [Axis] Frequent Flyer Program Revenue [Member] Frequent Flyer Program Revenue [Member] Frequent Flyer Program Revenue [Member] Frequent Flyer Program Liabilities [Member] Frequent Flyer Program Liabilities [Member] Frequent Flyer Program Liabilities [Member] Frequent Flyer Program [Line Items] Frequent Flyer Program [Line Items] [Line Items] for Frequent Flyer Program [Table] Other accrued liabilities Deferred revenue Other liabilities Total Liabilities Passenger revenues Other—net revenues Frequent Flyer Program Revenue Frequent Flyer Program Revenue Frequent Flyer Program Revenue Unrecorded Unconditional Purchase Obligation [Table] Unrecorded Unconditional Purchase Obligation [Table] Other Commitments [Axis] Other Commitments [Axis] Other Commitments [Domain] Other Commitments [Domain] Aircraft Maintenance Deposits [Member] Aircraft Maintenance Deposits [Member] Aircraft Maintenance Deposits [Member] Aircraft Maintenance and Parts Management [Member] Aircraft Maintenance and Parts Management [Member] Aircraft Maintenance and Parts Management [Member] Lease Arrangement, Type [Axis] Lease Arrangement, Type [Axis] Lease Arrangement, Type [Domain] Lease Arrangement, Type [Domain] Capacity Purchase Agreement with SkyWest [Member] Capacity Purchase Agreement with SkyWest [Member] Capacity Purchase Agreement with SkyWest [Member] Property Subject to or Available for Operating Lease [Axis] Property Subject to or Available for Operating Lease [Axis] Property Subject to or Available for Operating Lease [Domain] Property Subject to or Available for Operating Lease [Domain] Property Subject to Operating Lease [Member] Property Subject to Operating Lease [Member] Property Available for Operating Lease [Member] Property Available for Operating Lease [Member] Aircraft Type [Axis] Aircraft Type [Domain] Aircraft [Domain] B-737 [Member] Airbus [Member] Airbus [Member] Airbus [Member] B737-900ER [Member] B737-900ER [Member] B737 MAX [Member] B-737-Max [Member] Q400 [Member] Q400 [Member] Q400 [Member] A-320-Neo [Member] A-320-Neo [Member] A321neo [Member] A321neo [Member] A321neo [Member] E175 [Member] E175 [Member] E175 [Member] Property, Plant and Equipment, Type [Axis] Property, Plant and Equipment, Type [Domain] Aircraft Leases [Member] Aircraft [Member] Aircraft [Member] Facility Leases [Member] Building [Member] Unrecorded Unconditional Purchase Obligation by Category of Item Purchased [Axis] Unrecorded Unconditional Purchase Obligation by Category of Item Purchased [Axis] Unconditional Purchase Obligation, Category of Goods or Services Acquired [Domain] Unconditional Purchase Obligation, Category of Goods or Services Acquired [Domain] Aircraft Commitments [Member] Capital Addition Purchase Commitments [Member] Capacity Purchase Agreements [Member] Capacity [Member] Unrecorded Unconditional Purchase Obligation [Line Items] Unrecorded Unconditional Purchase Obligation [Line Items] Number of units involved in lease contracts Property Subject to or Available for Operating Lease, Number of Units Number of optional additional units Property Subject to or Available for Operating Lease, Number of Optional Additional Units Property Subject to or Available for Operating Lease, Number of Optional Additional Units Operating Leases, Future Minimum Payments Due, Fiscal Year Maturity [Abstract] Remainder of 2017 Operating Leases, Future Minimum Payments, Remainder of Fiscal Year 2018 Operating Leases, Future Minimum Payments, Due in Two Years 2019 Operating Leases, Future Minimum Payments, Due in Three Years 2020 Operating Leases, Future Minimum Payments, Due in Four Years 2021 Operating Leases, Future Minimum Payments, Due in Five Years Thereafter Operating Leases, Future Minimum Payments, Due Thereafter Total Operating Leases, Future Minimum Payments Due Unrecorded Unconditional Purchase Obligation, Fiscal Year Maturity [Abstract] Remainder of 2017 Unrecorded Unconditional Purchase Obligation, Due in Remainder of Fiscal Year 2018 Unrecorded Unconditional Purchase Obligation, Due within Two Years 2019 Unrecorded Unconditional Purchase Obligation, Due within Three Years 2020 Unrecorded Unconditional Purchase Obligation, Due within Four Years 2021 Unrecorded Unconditional Purchase Obligation, Due within Five Years Thereafter Unrecorded Unconditional Purchase Obligation, Due after Five Years Total Unrecorded Unconditional Purchase Obligation Rent Expense Operating Leases, Rent Expense Committed to Purchase (in Aircraft) Unrecorded Unconditional Purchase Obligation, Minimum Quantity Required Number Deferred (in Aircraft) Unrecorded Unconditional Purchase Obligation, Minimum Quantity Required, Number Deferred Unrecorded Unconditional Purchase Obligation, Minimum Quantity Required, Number Deferred Unrecorded Unconditional Purchase Obligation, Option to Cancel Unrecorded Unconditional Purchase Obligation, Option to Cancel Unrecorded Unconditional Purchase Obligation, Option to Cancel Options to Purchase Additional (in Aircraft) Unrecorded Unconditional Purchase Obligation, Option to Purchase Additional Unrecorded Unconditional Purchase Obligation, Option to Purchase Additional Capacity purchase arrangements (carriers) Airline, Capacity Purchase Arrangements, Carriers Airline, Capacity Purchase Arrangements, Carriers Schedule of Treasury Stock by Class Class of Treasury Stock [Table Text Block] Schedule of Accumulated Other Comprehensive Income (Loss) Schedule of Accumulated Other Comprehensive Income (Loss) [Table Text Block]