Basis of Presentation Basis of Presentation (Policies)	3 Months Ended
Basis of Presentation Basis of Presentation (Policies)	Mar. 31, 2016
Basis of Presentation [Abstract]
Basis of Presentation and New Accounting Pronouncements [Policy Text Block]	Basis of Presentation and New Accounting Pronouncements Heartland Express, Inc., (the “Company,” “we,” “us,” or “our”) is a holding company incorporated in Nevada, which owns all of the stock of Heartland Express Inc. of Iowa, Gordon Trucking, Inc. (“GTI”), Heartland Express Services, Inc., Heartland Express Maintenance Services, Inc., and A & M Express, Inc. We, and our subsidiaries, operate as one segment. We, together with our subsidiaries, are a short-to-medium haul truckload carrier (predominately 500 miles or less per load) with corporate headquarters in North Liberty, Iowa. We primarily provide nationwide asset-based dry van truckload service for major shippers from Washington to Florida and New England to California. The accompanying consolidated financial statements include the parent company, Heartland Express, Inc., and its subsidiaries, all of which are wholly owned. 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. generally accepted accounting principles 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, 2015 included in the Annual Report on Form 10-K of the Company filed with the Securities and Exchange Commission on February 29, 2016. 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 month period ended March 31, 2016, except as noted below in regards to the balance sheet classification of deferred taxes. In February 2016, the FASB issued ASU 2016-02, "Leases". This update seeks to increases the transparency and comparability among entities by requiring public entities to recognize lease assets and lease liabilities on the balance sheet and disclose key information about leasing arrangements. To satisfy the standard’s objective, a lessee will recognize a right-of-use asset representing its right to use the underlying asset for the lease term and a lease liability for the obligation to make lease payments. Both the right-of-use asset and lease liability will initially be measured at the present value of the lease payments, with subsequent measurement dependent on the classification of the lease as either a finance or an operating lease. For leases with a term of 12 months or less, a lessee is permitted to make an accounting policy election by class of underlying asset not to recognize lease assets and lease liabilities. If a lessee makes this election, it should recognize lease expense for such leases generally on a straight-line basis over the lease term. In transition, lessees are required to recognize and measure leases at the beginning of the earliest period presented using a modified retrospective approach. The modified retrospective approach includes a number of optional practical expedients that companies may elect to apply. These practical expedients relate to the identification and classification of leases that commenced before the effective date, initial direct costs for leases that commenced before the effective date, and the ability to use hindsight in evaluating lessee options to extend or terminate a lease or to purchase the underlying asset. The transition guidance also provides specific guidance for sale and leaseback transactions, build-to-suit leases, leveraged leases, and amounts previously recognized in accordance with the business combinations guidance for leases. The new standard is effective for public companies for annual periods beginning after December 15, 2018, and interim periods within those years, with early adoption permitted. The Company is currently evaluating the effect that adopting this standard will have on our consolidated financial statements. In November, 2015, the Financial Accounting Standards Board (FASB) issued Accounting Standards Update (ASU) 2015-17, "Balance Sheet Classification of Deferred Taxes". The ASU simplifies the current guidance, which requires entities to separately present deferred tax assets and liabilities as current and non-current in a classified balance sheet. The ASU will be effective for annual periods beginning after December 15, 2016, and interim periods within those years (with early adoption allowed). The Company adopted this guidance prospectively and classified deferred tax asset and deferred tax liability amounts, by tax jurisdiction, as non-currrent within our balance sheet at March 31, 2016 and for future periods. Prior periods presented have not been adjusted. In May, 2014, the FASB issued ASU 2014-09 which requires an entity to recognize the amount of revenue to which it expects to be entitled for the transfer of promised goods or services to customers. The guidance will replace most existing revenue recognition in GAAP when it becomes effective. The original guidance was to be effective for fiscal years, and interim periods within those years, beginning after December 15, 2016. In July 2015, the FASB issued ASU 2015-14 and agreed to defer the effective date of this guidance by one year, with early adoption permitted on the original effective date. The new guidance permits the use of either the retrospective or cumulative effect transition method. In March 2016, the FASB issued ASU 2016-08 which amends the guidance around principal versus agent and clarifies the control principle of goods and services. We are evaluating the effect that the new guidance will have on our consolidated financial statements and related disclosures. We have not yet selected a transition method nor have we determined the effect of the standard on our ongoing financial reporting.
Use of Estimates, Policy [Policy Text Block]	Use of Estimates The preparation of the consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates. There were no significant changes in estimates and assumptions used by management related to our critical accounting policies during the three months ended March 31, 2016.
Segment Reporting, Policy [Policy Text Block]	Segment Information We provide multiple transportation services across the United States (U.S.) and parts of Canada. We offer primarily asset-based transportation services in the dry van truckload market and also offer truckload temperature-controlled transportation services and non-asset based brokerage services. None of our transportation services or geographical-based regional terminals individually meet the definition of a segment. Our Chief Operating Decision Maker is our Chief Executive Officer who oversees and manages all of our transportation services and regional terminals, on a combined basis, including the legacy transportation services of acquired entities. As a result of the foregoing, we have determined that we have one segment, consistent with the authoritative accounting guidance on disclosures about segments of an enterprise and related information.
Cash and Cash Equivalents, Policy [Policy Text Block]	Cash and Cash Equivalents Cash equivalents are short-term, highly liquid investments with insignificant interest rate risk and original maturities of three months or less at acquisition.
Property, Plant and Equipment, Policy [Policy Text Block]	Depreciation for financial statement purposes is computed by the straight-line method for all assets other than tractors. We recognize depreciation expense on tractors using the 125% declining balance method. New tractors are depreciated to salvage values of $15,000 while new trailers are depreciated to salvage values of $4,000. Property and equipment are reported at cost, net of accumulated depreciation. Maintenance and repairs are charged to operations as incurred. Tires are capitalized separately from revenue equipment and are reported separately as “Prepaid tires” in the consolidated balance sheets and amortized over two years.
Goodwill and Intangible Assets, Policy [Policy Text Block]	All intangible assets determined to have finite lives are amortized over their estimated useful lives. The useful life of an intangible asset is the period over which the asset is expected to contribute directly or indirectly to future cash flows.
Earnings Per Share, Policy [Policy Text Block]	Earnings per Share Basic earnings per share is based upon the weighted average common shares outstanding during each year. Diluted earnings per share is based on the basic weighted earnings per share with additional weighted common shares for common stock equivalents.
Income Tax, Policy [Policy Text Block]	Income Taxes We use the asset and liability method of accounting for income taxes. Deferred tax assets and liabilities are recognized for the future tax consequences attributable to temporary differences between the financial statements carrying amount of existing assets and liabilities and their respective tax basis. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the years in which those temporary differences are expected to be recovered or settled. Such amounts are adjusted, as appropriate, to reflect changes in tax rates expected to be in effect when temporary differences reverse. The effect of a change in tax rates on deferred taxes is recognized in the period that the change is enacted. A valuation allowance is recorded to reduce the Company's deferred tax assets to the amount that is more likely than not to be realized.
Income Tax Uncertainties, Policy [Policy Text Block]	We recognize the effect of income tax positions only if those positions are more likely than not of being sustained. Recognized income tax positions are measured at the largest amount that is greater than 50% likely of being realized. Changes in recognition or measurement are reflected in the period in which the change in judgment occurs. We record interest and penalties related to unrecognized tax benefits in income tax expense.
Subsequent Events, Policy [Policy Text Block]	Subsequent Events We have evaluated events occurring subsequent to March 31, 2016 through the filing date of this Quarterly Report on Form 10-Q for disclosure.