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v3.20.4

Unusual or Infrequently Occurring Items (Details) |  | 3 Months Ended | 6 Months Ended | 9 Months Ended | 12 Months Ended | 60 Months Ended |
--- | --- | --- | --- | --- | --- | --- | ---
Apr. 20, 2020 $ / shares | Mar. 31, 2020 USD ($) | Sep. 30, 2020 USD ($) shares | Dec. 31, 2020 USD ($) | Dec. 31, 2020 USD ($) Aircraft | Dec. 31, 2019 USD ($) | Dec. 31, 2018 USD ($) | Apr. 30, 2025 | Dec. 27, 2020 USD ($)
Unusual or Infrequent Item, or Both [Line Items] |  |  |  |  |  |  |  |  |
Proceeds from Government Assistance, Payroll Support Program, CARES Act |  |  | $ 176,900,000 |  |  |  |  |  |
Proceeds From Payroll Support Program, Low-Interest Loan |  |  | $ 23,100,000 |  |  |  |  |  |
Class of Warrant or Right, Number of Securities Called by Warrants or Rights | shares |  |  | 27,681 |  |  |  |  |  |
Debt Instrument, Term | 10 years |  |  |  |  |  |  |  |
Class of Warrant or Right, Exercise Price of Warrants or Rights | $ / shares | $ 83.33 |  |  |  |  |  |  |  |
Total Proceeds To Be Provided to U.S. Airlines From Payroll Support Program Extension |  |  |  |  |  |  |  |  | $ 15,000,000,000.0
Operating Special Charge, Total |  |  |  |  | $ 306,299,000 |  |  |  |
Non-Operating Special Charge, Total |  |  |  |  | 26,632,000 |  |  |  |
Special Charges, Total |  |  |  |  | 332,931,000 |  |  |  |
Special charges |  |  |  |  | 161,600,000 | $ 0 | $ 0 |  |
Other Aircraft Related Costs |  |  |  |  | $ 98,000,000.0 |  |  |  |
Number of Aircraft Retired | Aircraft |  |  |  |  | 8 |  |  |  |
Number of Engines Retired | Aircraft |  |  |  |  | 5 |  |  |  |
Number of Aircraft In Sale-Leaseback Transactions | Aircraft |  |  |  |  | 8 |  |  |  |
Postemployment Benefits, Period Expense |  |  |  |  | $ 35,100,000 |  |  |  |
Termination Loans |  |  |  | $ 19,800,000 | 19,800,000 |  |  |  |
Other Expenses |  |  |  |  | $ 6,600,000 |  |  |  |
Proceeds Received From Payroll Support Program |  |  | $ 153,800,000 |  |  |  |  |  |
Fair Value of Common Stock Called by Warrants |  |  | 1,400,000 |  |  |  |  |  |
Unsecured Debt | Payroll Support Program Loan CARES Act [Member] |  |  |  |  |  |  |  |  |
Unusual or Infrequent Item, or Both [Line Items] |  |  |  |  |  |  |  |  |
Proceeds From Payroll Support Program, Low-Interest Loan |  |  | $ 23,100,000 |  |  |  |  |  |
Subsequent Event | Unsecured Debt | Payroll Support Program Loan CARES Act [Member] |  |  |  |  |  |  |  |  |
Unusual or Infrequent Item, or Both [Line Items] |  |  |  |  |  |  |  |  |
Debt Instrument, Interest Rate Terms |  |  |  |  |  |  |  | five years |
COVID19 [Member] |  |  |  |  |  |  |  |  |
Unusual or Infrequent Item, or Both [Line Items] |  |  |  |  |  |  |  |  |
Unusual Or Infrequent Item, Reduction Of Salary |  |  |  | 50.00% | 50.00% |  |  |  |
Allegiant Air |  |  |  |  |  |  |  |  |
Unusual or Infrequent Item, or Both [Line Items] |  |  |  |  |  |  |  |  |
Operating Special Charge |  |  |  |  | $ 141,713,000 |  |  |  |
Non-Operating Special Charge |  |  |  |  | 0 |  |  |  |
Special Charges, Total |  |  |  |  | 141,713,000 |  |  |  |
Special charges |  |  |  |  | 5,000,000.0 |  |  |  |
Postemployment Benefits, Period Expense |  |  |  |  | 32,100,000 |  |  |  |
Sunseeker Resorts |  |  |  |  |  |  |  |  |
Unusual or Infrequent Item, or Both [Line Items] |  |  |  |  |  |  |  |  |
Operating Special Charge |  |  |  |  | 137,994,000 |  |  |  |
Non-Operating Special Charge |  |  |  |  | 26,632,000 |  |  |  |
Special Charges, Total |  |  |  |  | 164,626,000 |  |  |  |
Special charges |  | $ 128,900,000 |  | $ 0 |  |  |  |  |
Postemployment Benefits, Period Expense |  |  |  |  | 2,900,000 |  |  |  |
Construction Suspension Expense |  |  |  |  | 5,000,000.0 |  |  |  |
Other |  |  |  |  |  |  |  |  |
Unusual or Infrequent Item, or Both [Line Items] |  |  |  |  |  |  |  |  |
Operating Special Charge |  |  |  |  | 26,592,000 |  |  |  |
Non-Operating Special Charge |  |  |  |  | 0 |  |  |  |
Special Charges, Total |  |  |  |  | 26,592,000 |  |  |  |
Special charges |  |  |  |  | $ 26,600,000 |  |  |  |
Kingsway Golf |  |  |  |  |  |  |  |  |
Unusual or Infrequent Item, or Both [Line Items] |  |  |  |  |  |  |  |  |
Special charges |  | $ 1,100,000 |  |  |  |  |  |  |

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