BASIS OF PRESENTATION (Policies)	9 Months Ended
Sep. 30, 2026
Accounting Policies [Abstract]
Basis of Presentation	United Airlines Holdings, Inc. (together with its consolidated subsidiaries, "UAL" or the "Company") is a holding company incorporated in Delaware and its wholly-owned subsidiary is United Airlines, Inc. (together with its consolidated subsidiaries, "United"). As UAL consolidates United for financial statement purposes, disclosures that relate to activities of United also apply to UAL, unless otherwise noted. United comprises substantially all of UAL's operating revenues, operating expenses, assets, liabilities and operating cash flows. When appropriate, UAL and United are named specifically for their individual contractual obligations and related disclosures, and any significant differences between the operations and results of UAL and United are separately disclosed and explained. The Company's consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America ("GAAP"). Some information and footnote disclosures normally included in financial statements have been condensed or omitted as permitted by the U.S. Securities and Exchange Commission (the "SEC"). The UAL and United financial statements should be read in conjunction with the information included in the Company's Annual Report on Form 10-K for the fiscal year ended December 31, 2025 (the "2025 Form 10-K"). The financial statements include all adjustments, including normal recurring adjustments and other adjustments, which are considered necessary for a fair presentation of the Company's financial position and results of operations for the interim periods presented. The Company's quarterly financial data is subject to seasonal fluctuations, and its second and third quarter financial results have historically reflected higher travel demand than its first and fourth quarter financial results. Due to these fluctuations, quarterly financial results are not necessarily indicative of financial results for the entire year. The Company consolidates variable interest entities when it determines that it is the primary beneficiary of those entities' operations. All material intercompany accounts and transactions have been eliminated in consolidation. Certain columns and rows within the financial statements and tables presented may not sum due to rounding. Per unit amounts have been calculated from the underlying whole-dollar amounts. Segments. The Company manages its operations as one segment. The Company's chief executive officer is its chief operating decision maker ("CODM"). The CODM assesses performance of the Company and makes resource allocation decisions based on Net income as reported in the Company's statement of consolidated operations. The significant segment expenses regularly provided to the CODM are those presented on the Company's statement of consolidated operations. The measure of segment assets is reported on the Company's consolidated balance sheets as Total assets.

United Airlines Holdings, Inc. (together with its consolidated subsidiaries, "UAL" or the "Company") is a holding company incorporated in Delaware and its wholly-owned subsidiary is United Airlines, Inc. (together with its consolidated subsidiaries, "United"). As UAL consolidates United for financial statement purposes, disclosures that relate to activities of United also apply to UAL, unless otherwise noted. United comprises substantially all of UAL's operating revenues, operating expenses, assets, liabilities and operating cash flows. When appropriate, UAL and United are named specifically for their individual contractual obligations and related disclosures, and any significant differences between the operations and results of UAL and United are separately disclosed and explained.

The Company's consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America ("GAAP"). Some information and footnote disclosures normally included in financial statements have been condensed or omitted as permitted by the U.S. Securities and Exchange Commission (the "SEC"). The UAL and United financial statements should be read in conjunction with the information included in the Company's Annual Report on Form 10-K for the fiscal year ended December 31, 2025 (the "2025 Form 10-K"). The financial statements include all adjustments, including normal recurring adjustments and other adjustments, which are considered necessary for a fair presentation of the Company's financial position and results of operations for the interim periods presented. The Company's quarterly financial data is subject to seasonal fluctuations, and its second and third quarter financial results have historically reflected higher travel demand than its first and fourth quarter financial results. Due to these fluctuations, quarterly financial results are not necessarily indicative of financial results for the entire year.

The Company consolidates variable interest entities when it determines that it is the primary beneficiary of those entities' operations. All material intercompany accounts and transactions have been eliminated in consolidation. Certain columns and rows within the financial statements and tables presented may not sum due to rounding. Per unit amounts have been calculated from the underlying whole-dollar amounts.

Segments. The Company manages its operations as one segment. The Company's chief executive officer is its chief operating decision maker ("CODM"). The CODM assesses performance of the Company and makes resource allocation decisions based on Net income as reported in the Company's statement of consolidated operations. The significant segment expenses regularly provided to the CODM are those presented on the Company's statement of consolidated operations. The measure of segment assets is reported on the Company's consolidated balance sheets as Total assets.