Document and Entity Information [Abstract] Entities [Table] Legal Entity [Axis] Entity [Domain] Represents the Retirement Plan Number 001. E B P 001 [Member] SKYWEST, INC. EMPLOYEES' RETIREMENT PLAN Entity Information [Line Items] Document Type Document Period End Date Entity Registrant Name Entity Tax Identification Number Entity tax identification number Entity Central Index Key Amendment Flag Statements of Assets Available for Benefits EBP, Statement of Net Asset Available for Benefit [Table] EBP, Statement of Net Asset Available for Benefit [Line Items] Statements of Assets Available for Benefits EBP, Asset [Abstract] Assets: EBP, Investment, Excluding Plan Interest in Master Trust, Fair Value Investments, at fair value Total investments at fair value EBP, Receivable [Abstract] Receivables EBP, Note Receivable from Participant Notes receivable from participants Amount of contribution receivable from employer of participant or participant in employee stock purchase, saving, or similar plan (employee benefit plan (EBP)). EBP, Contribution Receivable Contributions receivable EBP, Receivable Total receivables EBP, Net Asset Available for Benefit End of the year Beginning of the year Assets available for benefits Statement of Changes in Assets Available for Benefits EBP, Statement of Change in Net Asset Available for Benefit [Table] EBP, Statement of Change in Net Asset Available for Benefit [Line Items] Statement of Changes in Assets Available for Benefits EBP, Change in Net Asset Available for Benefit, Increase [Abstract] Additions: EBP, Change in Net Asset Available for Benefit, Increase from Contribution [Abstract] Contributions: EBP, Change in Net Asset Available for Benefit, Increase from Participant Contribution Participants EBP, Change in Net Asset Available for Benefit, Increase from Employer Contribution, Cash and Noncash Employer EBP, Change in Net Asset Available for Benefit, Increase from Contribution Total contributions EBP, Change in Net Asset Available for Benefit, Increase from Interest Income on Note Receivable from Participant Interest income on notes receivable from participants EBP, Change in Net Asset Available for Benefit, Increase (Decrease) from Income (Loss) on Investment [Abstract] Net investment income: EBP, Change in Net Asset Available for Benefit, Increase from Interest and Dividend Income on Investment Interest and dividends EBP, Change in Net Asset Available for Benefit, Increase (Decrease) from Unrealized Gain (Loss) on Investment Net appreciation in fair value of investments EBP, Change in Net Asset Available for Benefit, Increase (Decrease) from Income (Loss) on Investment Total net investment income EBP, Change in Net Asset Available for Benefit, Increase Total income and contributions EBP, Change in Net Asset Available for Benefit, Decrease [Abstract] Deductions: EBP, Change in Net Asset Available for Benefit, Decrease from Payment to Participant Distributions to participants EBP, Change in Net Asset Available for Benefit, Decrease from Administrative Expense Administrative expenses EBP, Change in Net Asset Available for Benefit, Decrease Total deductions EBP, Change in Net Asset Available for Benefit, Increase (Decrease) Net increase in assets available for benefits EBP, Change in Net Asset Available for Benefit, Increase (Decrease) [Abstract] Assets available for benefits: Description of the Plan EBP, Description of Plan [Table] EBP, Description of Plan [Line Items] Description of the Plan EBP, Description of Plan [Text Block] Description of the Plan Summary of Significant Accounting Policies EBP, Accounting Policy [Table] EBP, Accounting Policy [Line Items] Summary of Significant Accounting Policies EBP, Summary of Accounting Policy [Text Block] Summary of Significant Accounting Policies Party-in-Interest Transactions EBP, Related Party and Party-in-Interest Transactions [Table] EBP, Related Party and Party-in-Interest Transactions [Line Items] Party-in-Interest Transactions EBP, Related Party and Party-in-Interest Transactions [Text Block] Party-in-Interest Transactions Tax Status EBP, Tax Status [Table] EBP, Tax Status [Line Items] Tax Status EBP, Tax Status [Text Block] Tax Status Fair Value Measurements EBP, Investment, Fair Value and NAV [Table] EBP, Investment, Fair Value and NAV [Line Items] Fair Value Measurements EBP, Investment, Fair Value and NAV [Text Block] Fair Value Measurements Form 5500, Schedule H, Part IV, Line 4a - Schedule of Delinquent Participant Contributions. EBP, Schedule of Delinquent Participant Contribution [Table] EBP, Schedule of Delinquent Participant Contribution [Line Items] Form 5500, Schedule H, Part IV, Line 4a - Schedule of Delinquent Participant Contributions. EBP, Schedule of Delinquent Participant Contribution [Text Block] Form 5500, Schedule H, Part IV, Line 4a - Schedule of Delinquent Participant Contributions. Form 5500, Schedule H, Part IV, Line 4i - Schedule of Assets (Held at End of Year) EBP, Schedule of Asset Held for Investment [Table] EBP, Schedule of Asset Held for Investment [Line Items] Form 5500, Schedule H, Part IV, Line 4i - Schedule of Assets (Held at End of Year) EBP, Schedule of Asset Held for Investment [Text Block] Form 5500, Schedule H, Part IV, Line 4i - Schedule of Assets (Held at End of Year) EBP, Basis of Accounting [Policy Text Block] Basis of Accounting EBP, Use of Estimate [Policy Text Block] Use of Estimates EBP, Risk and Uncertainty [Policy Text Block] Risks and Uncertainties EBP, Investment [Policy Text Block] Investment Valuation and Income Recognition EBP, Payment to Participant [Policy Text Block] Distributions to Participants EBP, Note Receivable from Participant [Policy Text Block] Notes Receivable from Participants EBP, Contribution [Policy Text Block] Contributions EBP, Expense [Policy Text Block] Administrative Expenses Disclosure of accounting policy for interest and dividend income earned by employee stock purchase, saving, or similar plan (employee benefit plan (EBP)). Employee Benefit Plan, Interest And Dividend Income [Policy Text Block] Interest and Dividend Income EBP, Subsequent Event [Policy Text Block] Subsequent Events EBP, Investment, Fair Value and NAV [Table Text Block] Schedule of assets measured at fair value on a recurring basis Statistical Measurement [Axis] Statistical Measurement [Domain] Maximum [Member] Maximum Minimum [Member] Minimum Represents the minimum service period for employer matching contribution eligibility under (employee benefit plan (EBP)). Employee Benefit Plan, Minimum Service Period For Matching Contribution Eligibility Minimum service period for matching contribution eligibility EBP, Employer Contribution, Matching Percentage Employer contribution EBP, Participant Contribution, Automatic, Deferral Rate Participant's salary deferral contribution (in %) Percentage of employer nonelective contribution based on participant compensation in employee stock purchase, saving, or similar plan (employee benefit plan (EBP)). Employee Benefit Plan, Employer Contribution, Non-Elective Percentage Employer nonelective contribution percentage Represents the minimum service period required for eligibility to receive employer discretionary profit sharing contributions under the employee benefit plan (EBP). Employee Benefit Plan, Minimum Service Period For Profit Sharing Contribution Eligibility Minimum service period for profit sharing contribution eligibility Represents the percentage of vesting. Employee Benefit Plan, Vesting Percentage Vesting percentage Represents the period of vesting. Employee Benefit Plan, Vesting Period Vesting period EBP, Note Receivable from Participant, Account, Maximum Borrowing, Amount Note receivable, maximum borrowing amount EBP, Note Receivable from Participant, Account, Maximum Borrowing, to Total Account, Percentage Note receivable, maximum borrowing percentage EBP, Forfeited Nonvested Account Forfeited non-vested accounts EBP, Forfeited Nonvested Account, Decrease from Employer Contribution Amount of forfeited nonvested accounts used to offset employer contributions EBP, Related Party and Party-in-Interest [Axis] EBP, Related Party and Party-in-Interest [Axis] EBP, Related Party and Party-in-Interest [Domain] EBP, Related Party and Party-in-Interest [Domain] The participants in employee stock purchase, saving, or similar plan (employee benefit plan (EBP)). Employee Benefit Plan, Participants [Member] Participants EBP, Tax Determination Letter, Obtained [true false] Determination letter obtained EBP, Tax Determination Letter, Date Determination letter date EBP, Tax Qualification Status [Extensible Enumeration] Tax qualification status Investment Type [Axis] Investments [Domain] Mutual Fund [Member] Mutual funds EBP, Self-Directed Brokerage Account [Member] Self-directed brokerage accounts Cash and Cash Equivalents [Member] Cash and cash equivalents Common Collective Trust [Member] Common/collective trusts Represents the information pertaining to stable value funds. Stable Value Fund [Member] Stable value fund EBP, Employer, Common Stock Fund [Member] Common stock fund Fair Value Hierarchy and NAV [Axis] Fair Value Hierarchy and NAV [Domain] Fair Value, Inputs, Level 1, Level 2, and Level 3 [Member] Fair value Fair Value, Inputs, Level 1 [Member] Level 1 Fair Value Measured at Net Asset Value Per Share [Member] Net asset value per unit Common Stock [Member] Common Stock Fund (Common stock) Cash Equivalents [Member] Common Stock Fund (Cash equivalents) EBP, Fair Value, Investment, NAV, Redemption, Notice Period Redemption notice period EBP, Fair Value, Investment, NAV, Unfunded Commitment Unfunded commitments EBP, Investment, Number of Shares Number of shares held by the Plan EBP, Plan Number Plan number EBP, Schedule of Delinquent Participant Contribution, Transferred Late to Plan Participant Contributions Transferred Late to Plan EBP, Schedule of Delinquent Participant Contribution, Corrected Outside VFCP Contributions Corrected Outside VFCP Investment, Identifier [Axis] EBP, Investment, Issuer Name [Extensible Enumeration] EBP, Investment, Issuer Name [Extensible Enumeration] EBP, Asset Held for Investment, Investment, Excluding Plan Interest in Master Trust, Current Value Current Value EBP, Asset Held for Investment, Participant Loan, after Deemed Distribution Notes receivable from participants EBP, Asset Held for Investment, Participant Loan, Interest Rate Interest rates of notes receivable from participants EBP, Asset Held for Investment Total Investments and Loans EBP, Asset Held for Investment, Party-in-Interest [true false] EBP, Asset Held for Investment, Party-in-Interest [true false] EBP, Asset Held for Investment, Investment, Excluding Plan Interest in Master Trust, Participation Status [Extensible Enumeration] EBP, Asset Held for Investment, Investment, Excluding Plan Interest in Master Trust, Participation Status [Extensible Enumeration]