Regulatory Matters - Capital and Risk-Based Capital and Leverage Ratios (Details) $ in Thousands	Jun. 30, 2021 USD ($)	Dec. 31, 2020 USD ($)
Renasant corporation
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Tier 1 Capital to Average Assets (Leverage) - Amount	$ 1,385,657	$ 1,306,597
Tier 1 Capital to Average Assets (Leverage) - Ratio	0.0930	0.0937
Common Equity Tier 1 Capital to Risk-Weighted Assets - Amount	$ 1,278,165	$ 1,199,394
Common Equity Tier 1 Capital to Risk-Weighted Assets - Ratio	11.14%	10.93%
Tier 1 Capital to Risk-Weighted Assets - Amount	$ 1,385,657	$ 1,306,597
Tier 1 Capital to Risk-Weighted Assets - Ratio	0.1207	0.1191
Total Capital to Risk-Weighted Assets - Amount	$ 1,734,376	$ 1,653,694
Total Capital to Risk-Weighted Assets - Ratio	0.1511	0.1507
Renasant bank
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Tier 1 Capital to Average Assets (Leverage) - Amount	$ 1,444,582	$ 1,369,994
Tier 1 Capital to Average Assets (Leverage) - Ratio	0.0970	0.0983
Common Equity Tier 1 Capital to Risk-Weighted Assets - Amount	$ 1,444,582	$ 1,369,994
Common Equity Tier 1 Capital to Risk-Weighted Assets - Ratio	12.59%	12.49%
Tier 1 Capital to Risk-Weighted Assets - Amount	$ 1,444,582	$ 1,369,994
Tier 1 Capital to Risk-Weighted Assets - Ratio	0.1259	0.1249
Total Capital to Risk-Weighted Assets - Amount	$ 1,581,025	$ 1,504,985
Total Capital to Risk-Weighted Assets - Ratio	0.1378	0.1373