Impact of COVID-19	12 Months Ended
Impact of COVID-19	Dec. 31, 2021
Unusual or Infrequent Items, or Both [Abstract]
Impact of COVID-19	Impact of COVID-19 Since its initial onset in early 2020, the impact of the COVID-19 pandemic has evolved and continues to be fluid. As a result, the Company's financial and operational outlook remains subject to change. The Company continues to monitor the impacts of the pandemic on its operations and financial condition, and to adjust its mitigation and operational strategies. Impact on the Operations Beginning in March 2020, the Company began to experience significant fluctuations in demand due to the impacts of the COVID-19 pandemic. While the Company currently estimates that air travel demand will continue to fluctuate in the upcoming months as the effects of COVID-19 continue to develop, it expects that air travel demand will continue to recover in 2022. However, the situation continues to be fluid and actual capacity adjustments may be different than what the Company currently expects. The COVID-19 pandemic and its effects continue to evolve, with developments including: •Fluctuations in the rate of infections; •Infections from the identified Delta and Omicron variants; •The emergency use authorization issued by the U.S. Food and Drug Administration for COVID-19 vaccines; •Increases in the availability of COVID-19 vaccines resulting in expanded eligibility to more groups of people to receive the vaccine; •The approval of the Pfizer-BioNTech COVID-19 vaccine for persons aged 5 years and over; •The requirement, effective November 8, 2021, that all inbound international travelers, that are not U.S. citizens and not an immigrant (not a U.S. citizen, U.S. national, lawful permanent resident, or traveling to the United States on an immigrant visa) provide evidence of being fully vaccinated against COVID-19; and •The requirement, effective December 6, 2021, that all inbound international travelers (regardless of vaccination status or citizenship) provide a negative COVID-19 test no more than one day before traveling by air into the United States. On September 9, 2021, President Biden announced his Path Out of the Pandemic plan, which includes mandatory COVID-19 vaccination for certain employees in the private sector, the federal government, and health care settings. For private employers with 100 or more employees, President Biden's plan directed the Occupational Safety and Health Administration (OSHA) to issue an emergency temporary standard (ETS) requiring vaccination or weekly COVID-19 testing of all employees, absent disability or religious accommodations. The attorneys general of several states filed lawsuits challenging the ETS. On January 13, 2022, the Supreme Court blocked the Biden administration from enforcing its vaccine or test requirements for employers with 100 employees or more, however, each state may institute vaccination or testing requirements. The Company will continue to monitor the developments as it relates to this mandate. COVID-19 Legislation On April 20, 2020, the Company entered into a PSP Agreement with the United States Department of the Treasury ("Treasury"), pursuant to which the Company received a total of $344.4 million, used exclusively to pay for salaries, wages and benefits for the Company’s Team Members through September 30, 2020. Of that amount, $73.3 million is in the form of a low-interest 10-year loan. In addition, in connection with its participation in the PSP, the Company issued to the Treasury warrants pursuant to a warrant agreement to purchase up to 520,797 shares of the Company’s common stock at a strike price of $14.08 per share (the closing price for the shares of the Company's common stock on April 9, 2020) with a fair value of $3.9 million. The Company registered the resale of the warrants pursuant to the warrant agreement with the Treasury in September and October 2020. The remaining amount of $267.2 million, net of related costs, is in the form of a grant and was recognized in special charges (credits) in the Company's consolidated statement of operations in 2020. On December 27, 2020, the PSP2 was signed into law which extended the PSP portion of the CARES Act through March 31, 2021 and provided an additional $15 billion to fund the PSP2 for employees of passenger air carriers. The Company entered into the PSP2 payroll support program agreement with the Treasury on January 15, 2021. During the first and second quarters of 2021, the Company received a total of $212.1 million through the PSP2, used exclusively to pay for salaries, wages and benefits for the Company’s Team Members through March 31, 2021. In addition, the ARP, enacted on March 11, 2021, authorized the Treasury to provide additional assistance through the PSP3. Under the ARP, Treasury provided approximately $14 billion to fund the PSP3 for employees of passenger air carriers. The Company entered into the PSP3 payroll support program agreement with the Treasury on April 29, 2021. During the second quarter of 2021, the Company received a total of $197.9 million through the PSP3, to be used exclusively to pay for salaries, wages and benefits for the Company’s Team Members through September 30, 2021. Of the amounts received in 2021 mentioned above, $63.0 million is in the form of a low-interest 10-year loan. In addition, in connection with its participation in the PSP2 and PSP3, the Company issued to the Treasury warrants pursuant to a warrant agreement to purchase up to 137,753 shares and 80,539 shares of the Company’s common stock at a strike price of $24.42 per share (the closing price for the shares of the Company's common stock on December 24, 2020) and $36.45 (the closing price for the shares of the Company's common stock on March 10, 2021) with fair values of $2.8 million and $1.5 million, respectively. The Company registered the resale of the warrants pursuant to the warrant agreement with the Treasury in May 2021 and June 2021, respectively. The remaining amount of $342.7 million is in the form of a grant and was recognized in special credits in the Company's consolidated statement of operations in 2021. Total warrants issued in connection with the PSP, PSP2 and PSP3 represent less than 1% of the outstanding shares of the Company's common stock as of December 31, 2021. In connection with the Company's participation in the PSP2 and PSP3, the Company is subject to certain restrictions and limitations, including, but not limited to: •Restrictions on payment of dividends and stock buybacks through September 30, 2022; •Limits on executive compensation through April 1, 2023; •Restrictions from conducting involuntary furloughs or reducing pay rates and benefits until September 30, 2021, or the date on which all PSP funding has been expended; •Requirements to maintain certain levels of scheduled services through March 1, 2022; and •Reporting requirements. The CARES Act also provided an employee retention credit (“CARES Employee Retention credit”) which was a refundable tax credit against certain employment taxes. The Company qualified for the credit beginning on April 1, 2020 and received additional credits for qualified wages through December 31, 2020. The Consolidated Appropriations Act extended and expanded the availability of the CARES Employee Retention credit through June 30, 2021. Subsequently, the ARP extended and expanded the availability of the CARES Employee Retention credit through December 31, 2021, however, certain provisions apply only after December 31, 2020. During the twelve months ended December 31, 2021, the Company recorded the $37.5 million related to the CARES Employee Retention credit for the first and second quarters of 2021 within special credits on the Company’s consolidated statement of operations. The Company did not qualify for the employee retention credit for the third and fourth quarters of 2021. As of December 31, 2021, $40.8 million remained within accounts receivable, net on the Company's consolidated balance sheet related to the CARES employee retention credit for the fourth quarter of 2020 and first and second quarters of 2021. Refer to Note 5, Special Charges and Credits, for additional information. Finally, the CARES Act also provided for deferred payment of the employer portion of social security taxes through the end of 2020, with 50% of the deferred amount due December 31, 2021 and the remaining 50% due December 31, 2022. During 2020, the Company deferred $23.2 million in social security tax payments. As of December 31, 2021, $11.7 million of deferred social security tax payments remains within other current liabilities on the Company’s consolidated balance sheet. Income Taxes The Company's effective tax rate for the twelve months ended December 31, 2021 was 9.2% compared to 30.9% for the twelve months ended December 31, 2020. The decrease in tax rate, as compared to the prior year, is primarily due to a $56.1 million discrete federal tax benefit recorded during the twelve months ended December 31, 2020 related to the passage of the CARES Act. The 2020 discrete federal tax benefit reflects the impact of the CARES Act which allowed for carryback of net operating losses generated at a 21% tax rate to recover taxes paid at a 35% tax rate. In addition, the Company had an unfavorable permanent tax adjustment recorded during the twelve months ended December 31, 2021, related to the repurchase of a portion of the Company's 4.75% convertible notes due 2025. Excluding the impact from the unfavorable permanent tax adjustment, the Company's effective tax rate for the twelve months ended December 31, 2021 would have been 20.6%. While the Company expects its tax rate to be fairly consistent in the near term, it will tend to vary depending on recurring items such as the amount of income it earns in each state and the state tax rate applicable to such income. Discrete items particular to a given year may also affect the Company's effective tax rates. Balance Sheet, Cash Flow and Liquidity Since the onset of the COVID-19 pandemic in the U.S. in the first quarter of 2020, the Company has taken several actions to increase liquidity and strengthen its financial position. During the twelve months ended December 31, 2020, these actions included the private offering of $850.0 million of the 8.00% senior secured notes, the public offering of $175.0 million in the Company's 4.75% convertible notes due 2025, the public offering of 20,125,000 shares of the Company's voting common stock for which it received net proceeds of $192.4 million, the issuance and sale of 9,000,000 shares of the Company's voting common stock through its ATM Program for which it received net proceeds of $156.7 million and the execution of a revolving credit facility with a total commitment of $180.0 million as of December 31, 2020. During the first quarter of 2021, the Company entered into an amendment to this revolving credit facility which extended the maturity to March 30, 2024 and increased the commitment amount to $240.0 million. During the second quarter of 2021, the revolving credit facility was paid down in full and $240.0 million remained undrawn and available as of December 31, 2021. During the twelve months ended December 31, 2021, the Company further improved its liquidity and financial position through the public offering of $500.0 million in 1.00% convertible notes due 2026, the issuance of 10,594,073 shares of the Company's voting common stock for which it received net proceeds of $370.8 million, the extinguishment of $146.8 million in principal amount of the Company's 4.75% convertible notes due 2025 and the extinguishment of $340.0 million in principal amount of the Company's 8.00% senior secured notes. Refer to Note 14, Debt and Other Obligations and Note 11, Common Stock and Preferred Stock for additional information. As a result of these actions, as of December 31, 2021, the Company had $1,679.8 million of liquidity comprised of unrestricted cash and cash equivalents, short-term investment securities and funds available under its revolving credit facility due in 2024. The Omicron variant has significantly impacted staffing levels and disrupted travel across the industry and is expected to temporarily delay the demand recovery in early 2022. However, for purposes of assessing its liquidity needs, the Company estimates that air travel demand will continue to recover in 2022. The Company believes the actions taken since the onset of the COVID-19 pandemic address its future liquidity needs, but it may implement further discretionary changes and other cost reduction and liquidity preservation and/or enhancement measures, as needed, to address the volatility and quickly changing dynamics of passenger demand and the impact of revenue changes, regulatory and public health directives, prevailing government policy and financial market conditions. Workforce Actions As required by the PSP2, during the first quarter of 2021, the Company offered to rehire all eligible Team Members who were involuntarily terminated during 2020. For the twelve months ended December 31, 2021, the Company recorded $2.0 million in special charges within special credits on the Company’s consolidated statement of operations related to the rehiring of Team Members under its involuntary employee separation program. In addition, in response to increased air travel demand, during the first quarter of 2021, the Company requested the voluntary return to work of certain Team Members on leave under the Company's voluntary leave programs. As of December 31, 2021, all Team Members previously on voluntary leave had returned to work. Expenses related to voluntary leave programs were recorded within salaries, wages and benefits on the Company’s consolidated statement of operations. As the Company continues to monitor the impacts of the pandemic on its operations and financial condition, it will consider and evaluate the need for any additional workforce actions in future periods. In addition, the Company will continue monitor any government mandates related to vaccine, testing and other requirements.