Basis of Presentation	9 Months Ended
Sep. 30, 2016
Basis of Presentation [Abstract]
Basis of Presentation	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, Heartland Express Services, Inc., Heartland Express Maintenance Services, Inc., and A & M Express, Inc. Gordon Trucking, Inc. ("GTI") was merged into Heartland Express Inc. of Iowa effective July 1, 2016. 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 nine month period ended September 30, 2016, except as noted below in regards to the balance sheet classification of deferred taxes. In August 2016, the Financial Accounting Standards Boards (FASB) issued ASU 2016-15, “Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments,” which addresses eight specific cash flow issues with the objective of reducing the existing diversity in practice. The provisions of this update are effective for fiscal years beginning after December 15, 2017. Based on our initial assessment, we believe the impact of adoption of the standard will not have a material impact on our consolidated cash flows. In June 2016, the FASB issued ASU 2016-13, "Financial Instruments - Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments". This update requires measurement and recognition of expected versus incurred credit losses for financial assets held. ASU 2016-13 is effective for annual periods beginning after December 15, 2019, and interim periods therein. Based on our initial assessment, we believe the impact of adoption of the standard will not have a material impact on our financial statements. In March, 2016, the FASB issued ASU 2016-09, "Compensation-Stock Compensation (Topic 718): Improvements to Employee Share-Based Payment Accounting". This update seeks to simplify several aspects of the accounting for share-based payment transactions, including the income tax consequences, classification of awards as either equity or liabilities and classification on the statement of cash flows. This update becomes effective for the Company beginning January 1, 2017 with early adoption permitted. Based on our initial assessment, we believe the impact of adoption of the standard will not have a material impact on our financial statements. In February, 2016, the FASB issued ASU 2016-02, "Leases". This update seeks to increase 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. Based on our initial assessment, we believe the impact of adoption of the standard will not have a material impact on our financial statements. In November, 2015, the 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 beginning March 31, 2016 and for future periods. Prior periods presented have not been adjusted. In May 2014, the FASB issued Accounting Standards Update (ASU) 2014-09, Revenue from Contracts with Customers(Topic 606), which will replace numerous requirements in U.S. GAAP, including industry-specific requirements, and provide companies with a single revenue recognition model for recognizing revenue from contracts with customers. The core principle of the new standard is that a company should recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the company expects to be entitled in exchange for those goods or services. The two permitted transition methods under the new standard are the full retrospective method, in which case the standard would be applied to each prior reporting period presented and the cumulative effect of applying the standard would be recognized at the earliest period shown, or the modified retrospective method, in which case the cumulative effect of applying the standard would be recognized at the date of initial application. In July 2015, the FASB approved the deferral of the new standard's effective date by one year. The new standard is effective for annual reporting periods beginning after December 15, 2017. The FASB will permit companies to adopt the new standard early, but not before the original effective date of annual reporting periods beginning after December 15, 2016. We have been closely monitoring FASB activity related to the new standard and 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 final effect of the standard on our ongoing financial reporting however, based on our initial assessment, we believe the impact of adoption of the standard will not have a material impact on our operating revenue or operating income.

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, Heartland Express Services, Inc., Heartland Express Maintenance Services, Inc., and A & M Express, Inc. Gordon Trucking, Inc. ("GTI") was merged into Heartland Express Inc. of Iowa effective July 1, 2016. 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 nine month period ended September 30, 2016, except as noted below in regards to the balance sheet classification of deferred taxes.

In August 2016, the Financial Accounting Standards Boards (FASB) issued ASU 2016-15, “Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments,” which addresses eight specific cash flow issues with the objective of reducing the existing diversity in practice. The provisions of this update are effective for fiscal years beginning after December 15, 2017. Based on our initial assessment, we believe the impact of adoption of the standard will not have a material impact on our consolidated cash flows.

In June 2016, the FASB issued ASU 2016-13, "Financial Instruments - Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments". This update requires measurement and recognition of expected versus incurred credit losses for financial assets held. ASU 2016-13 is effective for annual periods beginning after December 15, 2019, and interim periods therein. Based on our initial assessment, we believe the impact of adoption of the standard will not have a material impact on our financial statements.

In March, 2016, the FASB issued ASU 2016-09, "Compensation-Stock Compensation (Topic 718): Improvements to Employee Share-Based Payment Accounting". This update seeks to simplify several aspects of the accounting for share-based payment transactions, including the income tax consequences, classification of awards as either equity or liabilities and classification on the statement of cash flows. This update becomes effective for the Company beginning January 1, 2017 with early adoption permitted. Based on our initial assessment, we believe the impact of adoption of the standard will not have a material impact on our financial statements.

In February, 2016, the FASB issued ASU 2016-02, "Leases". This update seeks to increase 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. Based on our initial assessment, we believe the impact of adoption of the standard will not have a material impact on our financial statements.

In November, 2015, the 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 beginning March 31, 2016 and for future periods. Prior periods presented have not been adjusted.

In May 2014, the FASB issued Accounting Standards Update (ASU) 2014-09, Revenue from Contracts with Customers(Topic 606), which will replace numerous requirements in U.S. GAAP, including industry-specific requirements, and provide companies with a single revenue recognition model for recognizing revenue from contracts with customers. The core principle of the new standard is that a company should recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the company expects to be entitled in exchange for those goods or services. The two permitted transition methods under the new standard are the full retrospective method, in which case the standard would be applied to each prior reporting period presented and the cumulative effect of applying the standard would be recognized at the earliest period shown, or the modified retrospective method, in which case the cumulative effect of applying the standard would be recognized at the date of initial application. In July 2015, the FASB approved the deferral of the new standard's effective date by one year. The new standard is effective for annual reporting periods beginning after December 15, 2017. The FASB will permit companies to adopt the new standard early, but not before the original effective date of annual reporting periods beginning after December 15, 2016. We have been closely monitoring FASB activity related to the new standard and 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 final effect of the standard on our ongoing financial reporting however, based on our initial assessment, we believe the impact of adoption of the standard will not have a material impact on our operating revenue or operating income.