Basis of Presentation	6 Months Ended
Jun. 30, 2023
Basis of Presentation and Accounting Pronouncements [Abstract]
Basis of Presentation and Significant Accounting Policies [Text Block]	Basis of Presentation and New Accounting PronouncementsHeartland Express, Inc. is a holding company incorporated in Nevada, which directly or indirectly owns all of the stock of the following active legal entities: Heartland Express, Inc. of Iowa, Heartland Express Services, Inc., Heartland Express Maintenance Services, Inc. ("Heartland Express"), and Midwest Holding Group, LLC and Millis Transfer, LLC ("Millis Transfer"), and Smith Transport, Inc., Smith Trucking, Inc., and Franklin Logistics, Inc. ("Smith Transport"), and CFI entities, Transportation Resources, Inc. and Contract Freighters, Inc. (collectively with certain Mexican entities, "CFI"). On May 31, 2022, Heartland Express, Inc. of Iowa acquired Smith Transport, a truckload carrier headquartered in Roaring Spring, Pennsylvania. On August 31, 2022, Heartland Express, Inc. of Iowa acquired CFI's non-dedicated U.S. dry van and temperature-controlled truckload business located in Joplin, Missouri, and certain Mexican entities (collectively "CFI Logistica") with operations located in Mexico. We, together with our subsidiaries, are a short, medium, and long-haul truckload carrier and transportation services provider. We primarily provide nationwide asset-based dry van truckload service for major shippers across the United States, along with cross-border freight and other transportation services offered through third party partnerships in Mexico.The accompanying consolidated financial statements include the parent company, Heartland Express, Inc., and its subsidiaries, all of which are wholly owned. Purchase accounting in relation to the acquisition of Smith Transport was deemed complete during the quarter ended June 30, 2023. All material intercompany items and transactions have been eliminated in consolidation. The accompanying unaudited consolidated financial statements of the Company have been prepared in accordance with U.S. generally accepted accounting principles ("GAAP") for interim financial information and with the instructions to Form 10-Q and Regulation S-X. Accordingly, they do not include all of the information and notes to the financial statements required by U.S. GAAP for complete financial statements. In the opinion of management, all normal, recurring adjustments considered necessary for a fair presentation have been included. The consolidated financial statements should be read in conjunction with the audited consolidated financial statements and accompanying notes for the year ended December 31, 2022 included in the Annual Report on Form 10-K the Company filed with the Securities and Exchange Commission (the "SEC") on March 1, 2023. Interim results of operations are not necessarily indicative of the results to be expected for the full year or any other interim periods. There were no changes to the Company's significant accounting policies during the three and six months ended June 30, 2023.

Basis of Presentation

6 Months Ended

Jun. 30, 2023

Basis of Presentation and Accounting Pronouncements [Abstract]

Basis of Presentation and Significant Accounting Policies [Text Block]

Basis of Presentation and New Accounting PronouncementsHeartland Express, Inc. is a holding company incorporated in Nevada, which directly or indirectly owns all of the stock of the following active legal entities: Heartland Express, Inc. of Iowa, Heartland Express Services, Inc., Heartland Express Maintenance Services, Inc. ("Heartland Express"), and Midwest Holding Group, LLC and Millis Transfer, LLC ("Millis Transfer"), and Smith Transport, Inc., Smith Trucking, Inc., and Franklin Logistics, Inc. ("Smith Transport"), and CFI entities, Transportation Resources, Inc. and Contract Freighters, Inc. (collectively with certain Mexican entities, "CFI"). On May 31, 2022, Heartland Express, Inc. of Iowa acquired Smith Transport, a truckload carrier headquartered in Roaring Spring, Pennsylvania. On August 31, 2022, Heartland Express, Inc. of Iowa acquired CFI's non-dedicated U.S. dry van and temperature-controlled truckload business located in Joplin, Missouri, and certain Mexican entities (collectively "CFI Logistica") with operations located in Mexico. We, together with our subsidiaries, are a short, medium, and long-haul truckload carrier and transportation services provider. We primarily provide nationwide asset-based dry van truckload service for major shippers across the United States, along with cross-border freight and other transportation services offered through third party partnerships in Mexico.The accompanying consolidated financial statements include the parent company, Heartland Express, Inc., and its subsidiaries, all of which are wholly owned. Purchase accounting in relation to the acquisition of Smith Transport was deemed complete during the quarter ended June 30, 2023. All material intercompany items and transactions have been eliminated in consolidation. The accompanying unaudited consolidated financial statements of the Company have been prepared in accordance with U.S. generally accepted accounting principles ("GAAP") for interim financial information and with the instructions to Form 10-Q and Regulation S-X. Accordingly, they do not include all of the information and notes to the financial statements required by U.S. GAAP for complete financial statements. In the opinion of management, all normal, recurring adjustments considered necessary for a fair presentation have been included. The consolidated financial statements should be read in conjunction with the audited consolidated financial statements and accompanying notes for the year ended December 31, 2022 included in the Annual Report on Form 10-K the Company filed with the Securities and Exchange Commission (the "SEC") on March 1, 2023. Interim results of operations are not necessarily indicative of the results to be expected for the full year or any other interim periods. There were no changes to the Company's significant accounting policies during the three and six months ended June 30, 2023.