Significant Accounting Policies (Policies)	3 Months Ended
Significant Accounting Policies (Policies)	Mar. 31, 2017
Accounting Policies [Abstract]
Basis of Accounting, Policy [Policy Text Block]	Basis of Presentation The condensed consolidated financial statements include the accounts of Covenant Transportation Group, Inc., a Nevada holding company, and its wholly owned subsidiaries. References in this report to "we," "us," "our," the "Company," and similar expressions refer to Covenant Transportation Group, Inc. and its wholly owned subsidiaries. All significant intercompany balances and transactions have been eliminated in consolidation. The accompanying unaudited condensed consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America for interim financial information and with the instructions to Form 10 -Q and Article 10 of Regulation S-X promulgated under the Securities Act of 1933. In preparing financial statements, it is necessary for management to make assumptions and estimates affecting the amounts reported in the condensed consolidated financial statements and related notes. These estimates and assumptions are developed based upon all information available. Actual results could differ from estimated amounts. In the opinion of management, the accompanying financial statements include all adjustments that are necessary for a fair presentation of the results for the interim periods presented, such adjustments being of a normal recurring nature. Certain information and footnote disclosures have been condensed or omitted pursuant to such rules and regulations. The December 31, 2016, condensed consolidated balance sheet was derived from our audited balance sheet as of that date. The Company’s operating results are subject to seasonal trends when measured on a quarterly basis; therefore operating results for the three months ended March 31, 2017 are not necessarily indicative of the results that may be expected for the year ending December 31, 2017. These condensed consolidated financial statements and notes thereto should be read in conjunction with the consolidated financial statements and notes thereto included in our Form 10 -K for the year ended December 31, 2016. Results of operations in interim periods are not necessarily indicative of results to be expected for a full year.
New Accounting Pronouncements, Policy [Policy Text Block]	Recent Accounting Pronouncements Accounting Standards not yet adopted In April 2015, the Financial Accounting Standards Board ("FASB") issued ASU 2015 - 14, which defers the effective date of ASU 2014 - 09. The new standard introduces a five -step model to determine when and how revenue is recognized. The premise of the new model is that an entity recognizes revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. The new standard will be effective for the Company for its annual reporting period beginning January 1, 2018, including interim periods within that reporting period. Early application is permitted for the annual periods beginning January 1, 2017. Entities are allowed to transition to the new standard by either recasting prior periods or recognizing the cumulative effect. We are in the process of evaluating the new standard, but we believe our revenue recognized under the new standard will generally approximate revenue recognized under current standards and, while we expect an impact to both revenue and certain variable expenses as a result of the adoption, we expect that the net impact to equity or earnings on a prospective basis will not be material. We plan to complete our evaluation during the remainder of 2017, including an assessment of the new expanded disclosure requirements and a final determination of the transition method we will use to adopt the new standard. In February 2016, FASB issued ASU 2016 - 02, which requires lessees to recognize a right-to-use asset and a lease obligation for all leases. Lessees are permitted to make an accounting policy election to not recognize an asset and liability for leases with a term of twelve months or less. Lessor accounting under the new standard is substantially unchanged. Additional qualitative and quantitative disclosures, including significant judgments made by management, will be required. This new standard will become effective for us in our annual reporting period beginning January 1, 2019, including interim periods within that reporting period and requires a modified retrospective transition approach. We are currently evaluating the impacts the adoption of this standard will have on the consolidated financial statements.
Property, Plant and Equipment, Policy [Policy Text Block]	Property and Equipment Property and equipment is stated at cost less accumulated depreciation. Depreciation for book purposes is determined using the straight-line method over the estimated useful lives of the assets, while depreciation for tax purposes is generally recorded using an accelerated method. Depreciation of revenue equipment is our largest item of depreciation. We have historically depreciated new tractors (excluding day cabs) over five years to salvage values of approximately 15% of their cost. We generally depreciate new trailers over seven years for refrigerated trailers and ten years for dry van trailers to salvage values of approximately 25% of their cost. We annually review the reasonableness of our estimates regarding useful lives and salvage values of our revenue equipment and other long-lived assets based upon, among other things, our experience with similar assets, conditions in the used revenue equipment market, and prevailing industry practice. Over the past several years, the price of new tractors has risen dramatically and there has been significant volatility in the used equipment market. As a result of the progressive decline in the market value of used tractors and our expectations that used tractor prices will not rebound in the near term, effective July 1, 2016 we reduced the salvage values on our tractors and, thus, prospectively increased depreciation expense. Estimates around the salvage values and useful lives for trailers remain unchanged. The impact in the third quarter of 2016 and in future quarters is approximately $2.0 million of additional depreciation expense per quarter or approximately $1.2 million per quarter net of tax, which represents approximately $0.06 per common or diluted share. Changes in the useful life or salvage value estimates, or fluctuations in market values that are not reflected in our estimates, could have a material effect on our results of operations. Gains and losses on the disposal of revenue equipment are included in depreciation expense in the consolidated statements of operations. We lease certain revenue equipment under capital leases with terms of approximately 60 to 84 months. Amortization of leased assets is included in depreciation and amortization expense. Although a portion of our tractors are protected by non-binding indicative trade-in values or binding trade-back agreements with the manufacturers, substantially all of our owned trailers are subject to fluctuations in market prices for used revenue equipment. Moreover, our trade-back agreements are contingent upon reaching acceptable terms for the purchase of new equipment. Declines in the price of used revenue equipment or failure to reach agreement for the purchase of new tractors with the manufacturers issuing trade-back agreements could result in impairment of, or losses on the sale of, revenue equipment.