Significant Accounting Policies (Policies)	9 Months Ended
Significant Accounting Policies (Policies)	Sep. 30, 2016
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, 2015, 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 and nine months ended September 30, 2016 are not necessarily indicative of the results that may be expected for the year ending December 31, 2016. 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, 2015. 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 adopted In March 2016, the Financial Accounting Standards Board issued Accounting Standards Update 2016-09, which changes the accounting for certain aspects of share-based payments to employees. The guidance requires the recognition of the income tax effects of awards in the income statement when the awards vest or are settled, thus eliminating additional paid in capital pools. The guidance also allows for the employer to repurchase more of an employee’s shares for tax withholding purposes without triggering liability accounting. In addition, the guidance allows for a policy election to account for forfeitures as they occur rather than on an estimated basis. The guidance is effective in 2017 with early adoption permitted. The Company has adopted this standard effective for the interim period ended June 30, 2016 resulting in the recording of $2.2 million to retained earnings as of the beginning of 2016 and $0.6 million of additional income tax benefit in the first quarter of 2016 as a result of previously unrecognized tax benefits resulting from our net operating loss carryovers. The statement of cash flows has not been adjusted for prior periods as we have adopted the statement of cash flow guidance prospectively.
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 25% of their cost. We generally depreciate new trailers over six years for refrigerated trailers and ten years for dry van trailers to salvage values of approximately 38% of their cost. As a result of the progressive decline in the 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.