BASIS OF PRESENTATION	9 Months Ended
Sep. 30, 2018
Accounting Policies [Abstract]
BASIS OF PRESENTATION	BASIS OF PRESENTATION Southwest Airlines Co. (the "Company" or "Southwest") operates Southwest Airlines, a major passenger airline that provides scheduled air transportation in the United States and near-international markets. The unaudited Condensed Consolidated Financial Statements include accounts of the Company and its wholly owned subsidiaries. The accompanying unaudited Condensed Consolidated Financial Statements of the Company and its subsidiaries have been prepared in accordance with accounting principles generally accepted in the United States for interim financial information and with the instructions to Form 10-Q and Article 10 of Regulation S-X. Accordingly, they do not include all of the information and footnotes required by generally accepted accounting principles in the United States ("GAAP") for complete financial statements. The unaudited Condensed Consolidated Financial Statements for the interim periods ended September 30, 2018 and 2017 include all adjustments which are, in the opinion of management, necessary for a fair presentation of the results for the interim periods. This includes all normal and recurring adjustments and elimination of significant intercompany transactions. Financial results for the Company and airlines in general can be seasonal in nature. In many years, the Company's revenues, as well as its Operating income and Net income, have been better in its second and third fiscal quarters than in its first and fourth fiscal quarters. Air travel is also significantly impacted by general economic conditions, the amount of disposable income available to consumers, unemployment levels, corporate travel budgets, natural disasters, and other factors beyond the Company's control. These and other factors, such as the price of jet fuel in some periods, the nature of the Company's fuel hedging program, and the periodic volatility of commodities used by the Company for hedging jet fuel, have created, and may continue to create, significant volatility in the Company's financial results. See Note 3 for further information on fuel and the Company's hedging program. Operating results for the three and nine months ended September 30, 2018, are not necessarily indicative of the results that may be expected for future quarters or for the year ended December 31, 2018. For further information, refer to the Consolidated Financial Statements and footnotes thereto included in the Southwest Airlines Co. Annual Report on Form 10-K for the year ended December 31, 2017. Effective as of January 1, 2018, the Company adopted Accounting Standards Update ("ASU") No. 2014-09, Revenue from Contracts with Customers, ASU No. 2017-07, Improving the Presentation of Net Periodic Pension Cost and Net Periodic Postretirement Benefit Cost, and ASU No. 2017-12, Targeted Improvements to Accounting for Hedging Activities. All amounts and disclosures set forth in this Form 10-Q reflect the adoption of these ASUs. See Note 2 for further information. The Company reclassified $51 million and $158 million from Aircraft rentals to Other operating expenses in the unaudited Condensed Consolidated Statement of Comprehensive Income for the three and nine months ended September 30, 2017, respectively, to be comparative with the current period's presentation. Aircraft rentals expense included in Other operating expenses for the three and nine months ended September 30, 2018, was $41 million and $121 million, respectively. This reclassification had no impact on Operating income, Net income, the unaudited Condensed Consolidated Balance Sheet, or the unaudited Condensed Consolidated Statement of Cash Flows.

BASIS OF PRESENTATION

Southwest Airlines Co. (the "Company" or "Southwest") operates Southwest Airlines, a major passenger airline that provides scheduled air transportation in the United States and near-international markets. The unaudited Condensed Consolidated Financial Statements include accounts of the Company and its wholly owned subsidiaries.

The accompanying unaudited Condensed Consolidated Financial Statements of the Company and its subsidiaries have been prepared in accordance with accounting principles generally accepted in the United States for interim financial information and with the instructions to Form 10-Q and Article 10 of Regulation S-X. Accordingly, they do not include all of the information and footnotes required by generally accepted accounting principles in the United States ("GAAP") for complete financial statements. The unaudited Condensed Consolidated Financial Statements for the interim periods ended September 30, 2018 and 2017 include all adjustments which are, in the opinion of management, necessary for a fair presentation of the results for the interim periods. This includes all normal and recurring adjustments and elimination of significant intercompany transactions. Financial results for the Company and airlines in general can be seasonal in nature. In many years, the Company's revenues, as well as its Operating income and Net income, have been better in its second and third fiscal quarters than in its first and fourth fiscal quarters. Air travel is also significantly impacted by general economic conditions, the amount of disposable income available to consumers, unemployment levels, corporate travel budgets, natural disasters, and other factors beyond the Company's control. These and other factors, such as the price of jet fuel in some periods, the nature of the Company's fuel hedging program, and the periodic volatility of commodities used by the Company for hedging jet fuel, have created, and may continue to create, significant volatility in the Company's financial results. See Note 3 for further information on fuel and the Company's hedging program. Operating results for the three and nine months ended September 30, 2018, are not necessarily indicative of the results that may be expected for future quarters or for the year ended December 31, 2018. For further information, refer to the Consolidated Financial Statements and footnotes thereto included in the Southwest Airlines Co. Annual Report on Form 10-K for the year ended December 31, 2017.

Effective as of January 1, 2018, the Company adopted Accounting Standards Update ("ASU") No. 2014-09, Revenue from Contracts with Customers, ASU No. 2017-07, Improving the Presentation of Net Periodic Pension Cost and Net Periodic Postretirement Benefit Cost, and ASU No. 2017-12, Targeted Improvements to Accounting for Hedging Activities. All amounts and disclosures set forth in this Form 10-Q reflect the adoption of these ASUs. See Note 2 for further information.

The Company reclassified $51 million and $158 million from Aircraft rentals to Other operating expenses in the unaudited Condensed Consolidated Statement of Comprehensive Income for the three and nine months ended September 30, 2017, respectively, to be comparative with the current period's presentation. Aircraft rentals expense included in Other operating expenses for the three and nine months ended September 30, 2018, was $41 million and $121 million, respectively. This reclassification had no impact on Operating income, Net income, the unaudited Condensed Consolidated Balance Sheet, or the unaudited Condensed Consolidated Statement of Cash Flows.