Regulatory Matters - Capital and Risk-Based Capital and Leverage Ratios (Details) $ in Thousands	Sep. 30, 2023 USD ($)	Dec. 31, 2022 USD ($)
Renasant Corporation
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Tier 1 Capital to Average Assets (Leverage) - Amount	$ 1,558,521	$ 1,481,197
Tier 1 Capital to Average Assets (Leverage) - Ratio	0.0948	0.0936
Common Equity Tier 1 Capital to Risk-Weighted Assets - Amount	$ 1,449,367	$ 1,372,747
Common Equity Tier 1 Capital to Risk-Weighted Assets - Ratio	10.46%	10.21%
Tier 1 Capital to Risk-Weighted Assets - Amount	$ 1,558,521	$ 1,481,197
Tier 1 Capital to Risk-Weighted Assets - Ratio	0.1125	0.1101
Total Capital to Risk-Weighted Assets - Amount	$ 2,065,992	$ 1,968,001
Total Capital to Risk-Weighted Assets - Ratio	0.1491	0.1463
Renasant Bank
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Tier 1 Capital to Average Assets (Leverage) - Amount	$ 1,698,680	$ 1,630,389
Tier 1 Capital to Average Assets (Leverage) - Ratio	0.1033	0.1030
Common Equity Tier 1 Capital to Risk-Weighted Assets - Amount	$ 1,698,680	$ 1,630,389
Common Equity Tier 1 Capital to Risk-Weighted Assets - Ratio	12.23%	12.10%
Tier 1 Capital to Risk-Weighted Assets - Amount	$ 1,698,680	$ 1,630,389
Tier 1 Capital to Risk-Weighted Assets - Ratio	0.1223	0.1210
Total Capital to Risk-Weighted Assets - Amount	$ 1,869,600	$ 1,781,312
Total Capital to Risk-Weighted Assets - Ratio	0.1346	0.1322