Debt Disclosure [Abstract] Line of Credit Facility [Table] Line of Credit Facility [Table] Subsequent Event Type [Axis] Subsequent Event Type [Axis] Subsequent Event Type [Domain] Subsequent Event Type [Domain] Subsequent Event [Member] Subsequent Event [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 other [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, Expiration Date Line of Credit Facility, Expiration Date 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 Cash, Cash Equivalents, and Short-term Investments [Abstract] CASH, CASH EQUIVALENTS AND MARKETABLE SECURITIES Cash, Cash Equivalents, and Marketable Securities [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] Equity [Abstract] 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] Schedule of Cash, Cash Equivalents and Short-term Investments Cash, Cash Equivalents and Investments [Table Text Block] Schedule of Realized Gain (Loss) Schedule of Realized Gain (Loss) [Table Text Block] Schedule of Debt Investment Maturities Investments Classified by Contractual Maturity Date [Table Text Block] OPERATING SEGMENT INFORMATION [Abstract] OPERATING SEGMENT INFORMATION [Abstract] Statement [Table] Statement [Table] Statement, Business Segments [Axis] Segments [Axis] Segment [Domain] Segments [Domain] Alaska Airlines [Member] Alaska Airlines [Member] Alaska Airlines [Member] Horizon [Member] Horizon [Member] Horizon Segment [Member] Parent [Member] Segment Reconciling Items [Member] Intersegment Elimination [Member] Intersegment Eliminations [Member] Statement [Line Items] Statement [Line Items] Total assets Assets Schedule of Stock by Class [Table] Schedule of Stock by Class [Table] Share Repurchase Program [Axis] Share Repurchase Program [Axis] Share Repurchase Program [Domain] Share Repurchase Program [Domain] September 2012 Stock Repurchase Program [Member] $250 million Repurchase Program [Member] $250 million Repurchase Program May 2014 Stock Repurchase Program [Member] 650 million dollar Repurchase Program [Member] 650 million dollar Repurchase Program [Member] 1 billion dollar Repurchase Program [Member] 1 billion dollar Repurchase Program [Member] 1 billion dollar 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 Stock repurchased during period Stock Repurchased During Period, Value 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 Accumulated Other Comprehensive Income (Loss), Net of Tax MILEAGE PLAN [Abstract] MILEAGE PLAN [Abstract] MILEAGE PLAN Mileage Plan Disclosure [Text Block] Mileage Plan Disclosure [Text Block] Fair Value Disclosures [Abstract] Fair Value, by Balance Sheet Grouping [Table] Fair Value, by Balance Sheet Grouping [Table] Fair Value, by Balance Sheet Grouping, Disclosure Item Amounts [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 Derivative Instruments and Hedging Activities Disclosure [Abstract] Derivative [Table] Derivative [Table] Hedging Designation [Axis] Hedging Designation [Domain] Not Designated as Hedging Instrument [Member] Not Designated as Hedging Instrument [Member] Derivative Instruments Designated as Hedges [Member] Designated as Hedging Instrument [Member] Derivative Instrument [Axis] Derivative Contract [Domain] Fuel hedge contracts [Member] Commodity Contract [Member] Aircraft Type [Axis] Aircraft Type [Axis] Aircraft Type [Domain] Aircraft [Domain] B737-800 [Member] B-737-800 [Member] Derivative [Line Items] Derivative [Line Items] Fuel hedge contracts outstanding (in barrels) Derivative, Nonmonetary Notional Amount Number of aircraft under operating lease (in Aircraft) Operating Leases, Number of Units Operating Leases, Number of Units Net cash received (paid) to for new positions and settlements Payments for (Proceeds from) Hedge, Investing Activities Posted collateral Derivative, Collateral, Right to Reclaim Cash LONG-TERM DEBT Long-term Debt [Text Block] 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] Postretirement Medical Benefits [Member] Other Postretirement Benefit Plan [Member] Defined Benefit Plan Disclosure [Line Items] Defined Benefit Plan Disclosure [Line Items] 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 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 Schedule of Available-for-sale Securities [Table] Schedule of Available-for-sale Securities [Table] Major Types of Debt and Equity Securities [Axis] Major Types of Debt and Equity Securities [Domain] 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] Schedule of Available-for-sale Securities [Line Items] Schedule of Available-for-sale Securities [Line Items] Cash and Cash Equivalents [Abstract] Cash Cash Cash equivalents Money Market Funds, at Carrying Value Cash and cash equivalents Cash and Cash Equivalents, at Carrying Value Available-for-sale Securities, Current [Abstract] Marketable securities, Cost Basis Available-for-sale Securities, Amortized Cost Basis Marketable securities, Unrealized Gains Available-for-sale Securities, Accumulated Gross Unrealized Gain, before Tax Marketable securities, Unrealized Losses Available-for-sale Securities, Accumulated Gross Unrealized Loss, before Tax Marketable securities, Fair Value Available-for-sale Securities, Current Cash and marketables securities, Cost Basis Total Cash And Marketable Securities, Amortized Cost Basis Total Cash And Marketable Securities, Amortized Cost Basis Cash and marketable securities, Unrealized Gains Cash and Available for Sale Securities Accumulated Gross Unrealized Gain Before Tax Cash and Available for Sale Securities Accumulated Gross Unrealized Gain Before Tax Cash and marketable securities, Unrealized Losses Cash and Available for Sale Securities Accumulated Gross Unrealized Loss Before Tax Cash and Available for Sale Securities Accumulated Gross Unrealized Loss Before Tax Total cash and marketable securities Cash, Cash Equivalents, and Short-term Investments Available-for-sale Securities, Activity [Abstract] Available-for-sale Securities, Activity [Abstract] Proceeds from sales and maturities Available-for-sale Securities, Gross Realized Gains (Losses), Sale Proceeds Gross realized gains Available-for-sale Securities, Gross Realized Gains Gross realized losses Available-for-sale Securities, Gross Realized Losses Commitments and Contingencies Disclosure [Abstract] COMMITMENTS Commitments Disclosure [Text Block] 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 2024 [Member] Fixed rate notes payable due through 2024 [Member] Fixed rate notes payable due through 2024 Variable-rate notes payable due through 2025 [Member] Variable rate notes payable due through 2025 [Member] Variable rate notes payable due through 2025 [Member] Debt Instrument [Line Items] Debt Instrument [Line Items] Total Long-term Debt Less current portion Long-term Debt, Current Maturities Long-term debt, less current portion Long-term Debt, Excluding Current Maturities 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 Debt payments Debt Instrument, Periodic Payment Income Statement [Abstract] Operating Revenues Revenues [Abstract] Passenger, Mainline Passenger Revenue, Mainline Passenger, Regional Passenger Revenue, Regional Total passenger revenue Passenger Revenue Freight and mail Cargo and Freight Revenue Other - net Other Revenue, Net Total Operating Revenues Revenue, Net Operating Expenses Operating Expenses [Abstract] Wages and benefits Labor and Related Expense Variable incentive pay Other Labor-related Expenses Aircraft fuel, including hedging gains and losses Fuel Costs 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 Other Other Cost and Expense, Operating Total Operating Expenses Operating Expenses Operating Income Operating Income (Loss) Nonoperating Income (Expense) Nonoperating Income (Expense) [Abstract] Interest income Investment Income, Interest Interest expense Interest Expense Interest capitalized Interest Costs Capitalized Adjustment Other - net Other Nonoperating Income (Expense) Nonoperating Income (Expense) Nonoperating Income (Expense) Income before income tax Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Extraordinary Items, Noncontrolling Interest Income tax expense Income Tax Expense (Benefit) Net Income Net Income (Loss) Attributable to Parent 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 Cash dividend declared per share (usd per share) Common Stock, Dividends, Per Share, Declared Segment Reporting [Abstract] Schedule of Segment Reporting Information, by Segment [Table] Schedule of Segment Reporting Information, by Segment [Table] Air Group Adjusted [Member] Air Group Adjusted [Member] Air Group Adjusted [Member] Alaska Mainline [Member] Alaska Mainline [Member] Alaska Mainline [Member] Alaska Regional [Member] Alaska Regional [Member] Alaska Regional [Member] Special Revenue and Charges [Member] Special Revenue and Charges [Member] Segment Reporting Information [Line Items] Segment Reporting Information [Line Items] Capacity purchase arrangements (percent) Airline, Capacity Purchase Arrangements, Percent Airline, Capacity Purchase Arrangements, Percent Number of operating airlines Number of Operating Airlines Number of Operating Airlines Number of operating segments Number of Operating Segments Operating revenues Passenger, Mainline Passenger, Regional CPA revenues Revenues Other - net Other Net and Special Revenue Other Net and Special Revenue Operating expenses Operating expenses, excluding fuel Operating Expenses, Excluding Fuel Operating Expenses, Excluding Fuel Economic fuel Interest expense Other Other Nonoperating Income Expense Other Other Nonoperating Income Expense Other Income (loss) before income tax 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] 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 Payments of Dividends Payments of Dividends FAIR VALUE MEASUREMENTS Fair Value Disclosures [Text Block] Statement of Cash Flows [Abstract] Cash flows from operating activities: Net Cash Provided by (Used in) Operating Activities [Abstract] Net Income 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 income taxes Increase (Decrease) in Deferred Income Taxes Increase in air traffic liability Increase (Decrease) in Air Traffic Liability Increase (decrease) 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 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 Proceeds from disposition of assets and changes in restricted deposits 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 Repayments of Long-term Debt Common stock repurchases Payments for Repurchase of Common Stock Dividends paid Other financing activities Proceeds from (Payments for) Other Financing Activities Net cash used in 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 paid (received) Income Taxes Paid, Net Non-cash transactions: Nonmonetary Transactions [Abstract] Schedule of Net Benefit Costs Schedule of Net Benefit Costs [Table Text Block] Statement of Comprehensive Income [Abstract] 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 gains (losses) arising during the period Other Comprehensive Income (Loss), Unrealized Holding Gain (Loss) on Securities Arising During Period, before Tax Reclassification of (gains) losses 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 gains (losses) arising during the period Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, before Tax Reclassification of (gains) losses 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 Schedule of Segment Reporting Information, by Segment Schedule of Segment Reporting Information, by Segment [Table Text Block] Schedule Of Mileage Plan [Table] Schedule of Mileage Plan [Table] Schedule of Mileage Plan [Table] Mileage Plan [Axis] Mileage Plan [Axis] Mileage Plan [Axis] Mileage Plan [Domain] Mileage Plan [Domain] Mileage Plan [Domain] Liabilities From Mileage Plan [Member] Liabilities From Mileage Plan [Member] Liabilities From Mileage Plan [Member] Revenue From Mileage Plan [Member] Revenue From Mileage Plan [Member] Revenue From Mileage Plan [Member] Mileage Plan [Line Items] Mileage Plan [Line Items] Mileage Plan [Line Items] Other accrued liabilities Accrued Liabilities, Current Deferred revenue Deferred Revenue Other liabilities Other Liabilities, Noncurrent Total Liabilities Passenger revenues Other - net revenues Total Mileage Plan Revenues Mileage Plan Revenue Mileage Plan Revenue Cost Basis [Abstract] 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 Fair Value [Abstract] 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 Marketable securities, Fair Value Mileage Plan Liabilities Mileage Plan Liabilities [Table Text Block] Mileage Plan Liabilities Mileage Plan Revenue Mileage Plan Revenue [Table Text Block] Mileage Plan Revenue [Table Text Block] EMPLOYEE BENEFIT PLANS Pension and Other Postretirement Benefits Disclosure [Text Block] Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Table] Fair Value Measurements, Recurring and Nonrecurring [Table] U.S. government and agency securities [Member] All other securities [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 Derivative instruments, liabilities Derivative Liability Accounting Policies [Abstract] GENERAL AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES Significant Accounting Policies [Text Block] OPERATING SEGMENT INFORMATION Segment Reporting Disclosure [Text Block] Fair Value, Measurement Inputs, Disclosure Fair Value, Measurement Inputs, Disclosure [Text Block] Fair Value, by Balance Sheet Grouping Fair Value, by Balance Sheet Grouping [Table Text Block] Fair Values Derivatives, Balance Sheet Location, by Derivative Contract Type [Table] Fair Values Derivatives, Balance Sheet Location, by Derivative Contract Type [Table] Derivative Instrument Risk [Axis] Derivative Contract Type [Domain] Hedging Designation [Axis] Hedging Designation [Domain] Derivative Instruments Not Designated as Hedges [Member] Derivatives, Fair Value, by Balance Sheet Location [Axis] Balance Sheet Location [Axis] Balance Sheet Location [Domain] Balance Sheet Location [Domain] Fuel hedge contracts [Member] Fuel Hedge Contracts, Current [Member] Fuel Hedge Contracts, Current [Member] Fuel hedge contracts, noncurrent assets [Member] Fuel Hedge Contracts, Noncurrent [Member] Fuel Hedge Contracts, Noncurrent [Member] Other accrued liabilities [Member] Other Accrued Liabilities [Member] Other Accrued Liabilities [Member] Other liabilities [Member] Other Liabilities [Member] Gains (losses) in AOCL [Member] Accumulated Other Comprehensive Income (Loss), Balance Sheet Location [Member] Accumulated Other Comprehensive Income Loss, Balance Sheet Location Derivatives, Fair Value [Line Items] Derivatives, Fair Value [Line Items] Derivative Assets, Current Derivative Asset, Current Derivative Assets, Noncurrent Derivative Asset, Noncurrent Derivative Liabilities, Current Derivative Liability, Current Derivative Liabilities, Noncurrent Derivative Liability, Noncurrent Losses in accumulated other comprehensive loss (AOCL) SHAREHOLDERS' EQUITY Stockholders' Equity Note Disclosure [Text Block] DERIVATIVE INSTRUMENTS Derivative Instruments and Hedging Activities Disclosure [Text Block] Statement of Financial Position [Abstract] 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 ASSETS Assets [Abstract] Current Assets Assets, Current [Abstract] Cash and cash equivalents Marketable securities Marketable Securities, Current Receivables - net Receivables, Net, Current Inventories and supplies - net Inventory, Net Deferred income taxes Deferred Tax Assets, Net of Valuation Allowance, Current 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 Other Assets Other Assets, Noncurrent Total 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 Other accrued liabilities Air traffic liability Deferred Air Traffic Revenue, Current Current portion of long-term debt Debt, Current Total Current Liabilities Liabilities, Current Long-Term Debt, Net of Current Portion Other Liabilities and Credits Liabilities, Noncurrent [Abstract] Deferred income taxes Deferred Tax Liabilities, Net, Noncurrent Deferred revenue Obligation for pension and postretirement medical benefits Pension and Other Postretirement Defined Benefit Plans, Liabilities, Noncurrent Other liabilities 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: 200,000,000 shares, Issued: 2015 - 128,409,720 shares; 2014 - 131,556,573 shares, Outstanding: 2015 - 126,701,469 shares; 2014 - 131,481,473 Common Stock, Value, Issued Capital in excess of par value Additional Paid in Capital, Common Stock Treasury stock (common), at cost: 2015 - 1,708,251 shares; 2014 - 75,100 shares Treasury Stock, Value Accumulated other comprehensive loss Retained earnings Retained Earnings (Accumulated Deficit) Total Shareholders' Equity Stockholders' Equity Attributable to Parent Total Liabilities and Shareholders' Equity Liabilities and Equity Organization and Basis of Presentation Basis of Accounting, Policy [Policy Text Block] Recently Issued Accounting Pronouncements New Accounting Pronouncements, Policy [Policy Text Block] Unrecorded Unconditional Purchase Obligation [Table] Unrecorded Unconditional Purchase Obligation [Table] 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] Airline Capacity Purchase Arrangements [Member] Property, Plant and Equipment, Type [Axis] Property, Plant and Equipment, Type [Axis] Property, Plant and Equipment, Type [Domain] Property, Plant and Equipment, Type [Domain] Aircraft [Member] Aircraft [Member] Aircraft [Member] Building [Member] Building [Member] Lease Arrangement, Type [Axis] Lease Arrangement, Type [Axis] Lease Arrangement, Type [Domain] Lease Arrangement, Type [Domain] Operated by Skywest [Member] Property Subject to Operating Lease [Member] Subleased and Operated by Other Carrier [Member] Property Available for Operating Lease [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] Non Operating Aircraft [Member] Non Operating Aircraft [Member] Non Operating Aircraft [Member] Operating Aircraft [Member] Operating Aircraft [Member] Operating Aircraft [Member] B-737 [Member] B-737 [Member] B737-900ER [Member] B737-900ER [Member] B737-900ER [Member] B-737-Max [Member] B-737-Max [Member] Q400 [Member] Q400 [Member] Q400 [Member] CRJ-700 [Member] CRJ-700 [Member] E175 [Member] Original E175 [Member] Original E175 [Member] Delivered E175 [Member] Delivered E175 [Member] Delivered E175 [Member] E-175 [Domain] E-175 [Domain] E-175 [Domain] Additional E175 [Member] Additional E175 [Member] Additional E175 [Member] Unrecorded Unconditional Purchase Obligation [Line Items] Unrecorded Unconditional Purchase Obligation [Line Items] Operating Leases, Future Minimum Payments Due, Fiscal Year Maturity [Abstract] Remainder of 2015 Operating Leases, Future Minimum Payments, Remainder of Fiscal Year 2016 Operating Leases, Future Minimum Payments, Due in Two Years 2017 Operating Leases, Future Minimum Payments, Due in Three Years 2018 Operating Leases, Future Minimum Payments, Due in Four Years 2019 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 2015 Unrecorded Unconditional Purchase Obligation, Due in Remainder of Fiscal Year 2016 Unrecorded Unconditional Purchase Obligation, Due within Two Years 2017 Unrecorded Unconditional Purchase Obligation, Due within Three Years 2018 Unrecorded Unconditional Purchase Obligation, Due within Four Years 2019 Unrecorded Unconditional Purchase Obligation, Due within Five Years Thereafter Unrecorded Unconditional Purchase Obligation, Due after Five Years Total Unrecorded Unconditional Purchase Obligation Committed to Purchase (in Aircraft) Unrecorded Unconditional Purchase Obligation, Minimum Quantity Required 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 Number of aircraft under capacity purchase agreement Number of Aircraft under Capacity Purchase Agreement Number of Aircraft under Capacity Purchase Agreement Number of additional aircraft that could be leased (in aircraft) Operating Leases, Number of Additional Units That Could Be Leased Operating Leases, Number of Additional Units That Could Be Leased Rent expense Operating Leases, Rent Expense Long-term Debt, Fiscal Year Maturity [Abstract] Long-term Debt, Fiscal Year Maturity [Abstract] Remainder of 2015 Long-term Debt, Maturities, Repayments of Principal, Remainder of Fiscal Year 2016 Long-term Debt, Maturities, Repayments of Principal in Year Two 2017 Long-term Debt, Maturities, Repayments of Principal in Year Three 2018 Long-term Debt, Maturities, Repayments of Principal in Year Four 2019 Long-term Debt, Maturities, Repayments of Principal in Year Five Thereafter Long-term Debt, Maturities, Repayments of Principal after Year Five Derivative Instruments, Gain (Loss) by Hedging Relationship, by Income Statement Location, by Derivative Instrument Risk [Table] Derivative Instruments, Gain (Loss) [Table] Balance Sheet Location [Axis] Hedging Relationship [Axis] Hedging Relationship [Domain] Cash Flow Hedging [Member] Income Statement Location [Axis] Income Statement Location [Axis] Income Statement Location [Domain] Income Statement Location [Domain] Gains (losses) recognized in aircraft fuel expense [Member] Aircraft Fuel Expense [Member] Aircraft Fuel Expense [Member] Gains (losses) recognized in aircraft rent [Member] Aircraft Rent [Member] Aircraft Rent [Member] Derivative Instruments, Gain (Loss) [Line Items] Derivative Instruments, Gain (Loss) [Line Items] Gain (losses) recognized in income Derivative, Gain (Loss) on Derivative, Net Gains (losses) recognized in other comprehensive income (OCI) Derivative Instruments, Gain (Loss) Recognized in Other Comprehensive Income (Loss), Effective Portion, Net Derivative Gain (Loss) in Accumulated Other Comprehensive Loss To Be Reclassified Within Next Twelve Months Price Risk Cash Flow Hedge Unrealized Gain (Loss) to be Reclassified During Next 12 Months Schedule of Derivative Instruments in Statement of Financial Position, Fair Value Schedule of Derivative Instruments in Statement of Financial Position, Fair Value [Table Text Block] Schedule of Derivative Instruments, Gain (Loss) in Statement of Financial Performance Derivative Instruments, Gain (Loss) [Table Text Block]