Legal Matters	6 Months Ended
Jun. 30, 2015
Loss Contingency [Abstract]
Legal matters	NOTE 8 – LEGAL MATTERS O'Reilly is currently involved in litigation incidental to the ordinary conduct of the Company's business. The Company records reserves for litigation losses in instances where a material adverse outcome is probable and the Company is able to reasonably estimate the probable loss. The Company reserves for an estimate of material legal costs to be incurred in pending litigation matters. Although the Company cannot ascertain the amount of liability that it may incur from any of these matters, it does not currently believe that, in the aggregate, these matters, taking into account applicable insurance and reserves, will have a material adverse effect on its consolidated financial position, results of operations or cash flows in a particular quarter or annual period. As previously reported, the Company received a subpoena from the District Attorney of the County of Alameda, along with other environmental prosecutorial offices in the state of California, seeking documents and information related to the handling, storage and disposal of hazardous waste. Management has an ongoing and open dialogue with these agencies regarding this matter and is cooperating fully with the request; however, at this time a prediction of the ultimate outcome of these efforts cannot be determined. On June 18, 2015, a jury in Greene County, Missouri returned an unfavorable verdict in a litigated contract dispute in the matter Meridian Creative Alliance vs. O’Reilly Automotive Stores, Inc, et. al. in the amount of $12.5 million. Following the verdict, Meridian Creative Alliance indicated that it intends to seek attorney’s fees as provided in the contract, as well as prejudgment interest and associated costs, all of which the Company intends to contest prior to the trial court’s entry of a final judgment. The Company strongly believes that the verdict was unjust and unsupported by the law and the underlying facts and, further, that there are several potential bases for a new trial or reversal on appeal. The Company intends to vigorously challenge the verdict in the trial court and, if necessary, appeal. In the interim, the Company has accrued $19.0 million in the second quarter to include the verdict amount and estimated attorney fees and pre-judgment interest that may be awarded by the trial court along with certain costs associated with the post-trial and appeal process.

NOTE 8 – LEGAL MATTERS

O'Reilly is currently involved in litigation incidental to the ordinary conduct of the Company's business. The Company records reserves for litigation losses in instances where a material adverse outcome is probable and the Company is able to reasonably estimate the probable loss. The Company reserves for an estimate of material legal costs to be incurred in pending litigation matters. Although the Company cannot ascertain the amount of liability that it may incur from any of these matters, it does not currently believe that, in the aggregate, these matters, taking into account applicable insurance and reserves, will have a material adverse effect on its consolidated financial position, results of operations or cash flows in a particular quarter or annual period.

As previously reported, the Company received a subpoena from the District Attorney of the County of Alameda, along with other environmental prosecutorial offices in the state of California, seeking documents and information related to the handling, storage and disposal of hazardous waste. Management has an ongoing and open dialogue with these agencies regarding this matter and is cooperating fully with the request; however, at this time a prediction of the ultimate outcome of these efforts cannot be determined.

On June 18, 2015, a jury in Greene County, Missouri returned an unfavorable verdict in a litigated contract dispute in the matter Meridian Creative Alliance vs. O’Reilly Automotive Stores, Inc, et. al. in the amount of $12.5 million. Following the verdict, Meridian Creative Alliance indicated that it intends to seek attorney’s fees as provided in the contract, as well as prejudgment interest and associated costs, all of which the Company intends to contest prior to the trial court’s entry of a final judgment. The Company strongly believes that the verdict was unjust and unsupported by the law and the underlying facts and, further, that there are several potential bases for a new trial or reversal on appeal. The Company intends to vigorously challenge the verdict in the trial court and, if necessary, appeal. In the interim, the Company has accrued $19.0 million in the second quarter to include the verdict amount and estimated attorney fees and pre-judgment interest that may be awarded by the trial court along with certain costs associated with the post-trial and appeal process.