| Document and Entity Information | Nov. 24, 2021 |
| Cover [Abstract] | |
| Entity Registrant Name | RENASANT CORP |
| Amendment Flag | false |
| Entity Central Index Key | 0000715072 |
| Document Type | 8-K |
| Document Period End Date | Nov. 24, 2021 |
| Entity Incorporation State Country Code | MS |
| Entity File Number | 001-13253 |
| Entity Tax Identification Number | 64-0676974 |
| Entity Address, Address Line One | 209 Troy Street |
| Entity Address, City or Town | Tupelo |
| Entity Address, State or Province | MS |
| Entity Address, Postal Zip Code | 38804-4827 |
| City Area Code | (662) |
| Local Phone Number | 680-1001 |
| Written Communications | false |
| Soliciting Material | false |
| Pre Commencement Tender Offer | false |
| Pre Commencement Issuer Tender Offer | false |
| Security 12b Title | Common stock, $5.00 par value per share |
| Trading Symbol | RNST |
| Security Exchange Name | NASDAQ |
| Entity Emerging Growth Company | false |
