| Document and Entity Information | Mar. 28, 2024 |
| Document And Entity Information [Line Items] | |
| Document Type | 8-K |
| Document Period End Date | Mar. 28, 2024 |
| Entity Registrant Name | ATMOS ENERGY CORP |
| Entity Incorporation State Country Code | TX |
| Entity File Number | 1-10042 |
| Entity Tax Identification Number | 75-1743247 |
| Entity Address Address Line 1 | 1800 THREE LINCOLN CENTRE |
| Entity Address Address Line 2 | 5430 LBJ FREEWAY |
| Entity Address City Or Town | DALLAS |
| Entity Address State Or Province | TX |
| Entity Address Postal Zip Code | 75240 |
| City Area Code | 972 |
| Local Phone Number | 934-9227 |
| Written Communications | false |
| Soliciting Material | false |
| Pre Commencement Tender Offer | false |
| Pre Commencement Issuer Tender Offer | false |
| Security 12b Title | Common stock, No Par Value |
| Trading Symbol | ATO |
| Security Exchange Name | NYSE |
| Entity Emerging Growth Company | false |
| Amendment Flag | false |
| Entity Central Index Key | 0000731802 |
| VA | |
| Document And Entity Information [Line Items] | |
| Entity Incorporation State Country Code | VA |
