Regulatory Matters - Capital and Risk-Based Capital and Leverage Ratios (Details) $ in Thousands	Sep. 30, 2022 USD ($)	Dec. 31, 2021 USD ($)
Renasant Corporation
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Tier 1 Capital to Average Assets (Leverage) - Amount	$ 1,493,705	$ 1,422,077
Tier 1 Capital to Average Assets (Leverage) - Ratio	0.0939	0.0915
Common Equity Tier 1 Capital to Risk-Weighted Assets - Amount	$ 1,385,489	$ 1,314,295
Common Equity Tier 1 Capital to Risk-Weighted Assets - Ratio	10.64%	11.18%
Tier 1 Capital to Risk-Weighted Assets - Amount	$ 1,493,705	$ 1,422,077
Tier 1 Capital to Risk-Weighted Assets - Ratio	0.1147	0.1210
Total Capital to Risk-Weighted Assets - Amount	$ 1,973,206	$ 1,897,167
Total Capital to Risk-Weighted Assets - Ratio	0.1515	0.1614
Renasant Bank
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Tier 1 Capital to Average Assets (Leverage) - Amount	$ 1,645,539	$ 1,580,904
Tier 1 Capital to Average Assets (Leverage) - Ratio	0.1034	0.1018
Common Equity Tier 1 Capital to Risk-Weighted Assets - Amount	$ 1,645,539	$ 1,580,904
Common Equity Tier 1 Capital to Risk-Weighted Assets - Ratio	12.61%	13.46%
Tier 1 Capital to Risk-Weighted Assets - Amount	$ 1,645,539	$ 1,580,904
Tier 1 Capital to Risk-Weighted Assets - Ratio	0.1261	0.1346
Total Capital to Risk-Weighted Assets - Amount	$ 1,789,382	$ 1,697,163
Total Capital to Risk-Weighted Assets - Ratio	0.1371	0.1444