| Cover | Aug. 19, 2024 |
| Cover [Abstract] | |
| Document Type | 8-K |
| Amendment Flag | false |
| Document Period End Date | Aug. 19, 2024 |
| Entity File Number | 000-21318 |
| Entity Registrant Name | O REILLY AUTOMOTIVE INC |
| Entity Central Index Key | 0000898173 |
| Entity Tax Identification Number | 27-4358837 |
| Entity Incorporation, State or Country Code | MO |
| Entity Address, Address Line One | 233 South Patterson Avenue |
| Entity Address, City or Town | Springfield |
| Entity Address, State or Province | MO |
| Entity Address, Postal Zip Code | 65802 |
| City Area Code | 417 |
| Local Phone Number | 862-6708 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Title of 12(b) Security | Common Stock $0.01 par value |
| Trading Symbol | ORLY |
| Security Exchange Name | NASDAQ |
| Entity Emerging Growth Company | false |
