Legal Matters	9 Months Ended
Sep. 30, 2016
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. The Company expects the District Attorney will seek injunctive and monetary relief. 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 although the Company has accrued all amounts that it believes to be probable and reasonably estimable and does not believe that the ultimate resolution of this matter will have a material adverse effect on its consolidated financial position, results of operations or cash flows. As previously reported, 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. 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 reversal on appeal. The Company is vigorously challenging the verdict in the Court of Appeals. As of September 30, 2016, the Company had reserved $18.6 million with respect to this matter.

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. The Company expects the District Attorney will seek injunctive and monetary relief. 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 although the Company has accrued all amounts that it believes to be probable and reasonably estimable and does not believe that the ultimate resolution of this matter will have a material adverse effect on its consolidated financial position, results of operations or cash flows.

As previously reported, 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. 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 reversal on appeal. The Company is vigorously challenging the verdict in the Court of Appeals. As of September 30, 2016, the Company had reserved $18.6 million with respect to this matter.