| Document and Entity Information | Jun. 30, 2020 |
| Cover [Abstract] | |
| Entity Central Index Key | 0000040987 |
| Amendment Flag | false |
| Document Type | 8-K |
| Document Period End Date | Jun. 30, 2020 |
| Entity File Number | 001-05690 |
| Entity Registrant Name | GENUINE PARTS CO |
| Entity Incorporation, State or Country Code | GA |
| Entity Tax Identification Number | 58-0254510 |
| Entity Address, Address Line One | 2999 WILDWOOD PARKWAY, |
| Entity Address, Postal Zip Code | 30339 |
| Entity Address, City or Town | ATLANTA, |
| Entity Address, State or Province | GA |
| City Area Code | 678 |
| Local Phone Number | 934-5000 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Title of 12(b) Security | Common Stock, $1.00 par value per share |
| Trading Symbol | GPC |
| Security Exchange Name | NYSE |
| Entity Emerging Growth | false |
