Renasant Corporation (Parent Company Only) Condensed Financial Information - Balance Sheets (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Assets
Cash and cash equivalents	$ 569,111	$ 281,453	$ 306,224	$ 211,571
Loans, net	9,034,103	7,574,111
Other assets	202,621	144,667
Total assets	12,934,878	9,829,981	8,699,851
Liabilities and shareholders’ equity
Other liabilities	111,084	96,563
Shareholders’ equity	2,043,913	1,514,983	1,232,883	1,036,818
Total liabilities and shareholders’ equity	12,934,878	9,829,981
Cash collateral	3,737	3,643
Renasant Corporation
Assets
Cash and cash equivalents	44,581	81,839	$ 121,233	$ 11,107
Investments	1,662	2,734
Loans, net	640	0
Investment in bank subsidiary	2,236,932	1,618,993
Accrued interest receivable on bank balances	6	6
Intercompany receivable	1,618	4,210
Other assets	18,574	10,839
Total assets	2,304,013	1,718,621
Liabilities and shareholders’ equity
Junior subordinated debentures	109,636	85,881
Subordinated notes	147,239	114,074
Other liabilities	3,225	3,683
Shareholders’ equity	2,043,913	1,514,983
Total liabilities and shareholders’ equity	$ 2,304,013	$ 1,718,621