Renasant Corporation (Parent Company Only) Condensed Financial Information (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Assets
Cash and cash equivalents	$ 281,453	$ 306,224	$ 211,571	$ 161,583
Other assets	144,667	149,522
Total assets	9,829,981	8,699,851	7,926,496
Liabilities and shareholders’ equity
Other liabilities	96,563	95,696
Total shareholders’ equity	1,514,983	1,232,883	1,036,818	711,651
Total liabilities and shareholders’ equity	9,829,981	8,699,851
Cash collateral			1,970
Renasant Corporation
Assets
Cash and cash equivalents	81,839	121,233	$ 11,107	$ 9,968
Investments	2,734	4,327
Investment in bank subsidiary	1,618,993	1,291,686
Accrued interest receivable on bank balances	6	5
Intercompany receivable	4,210	2,771
Other assets	10,839	11,508
Total assets	1,718,621	1,431,530
Liabilities and shareholders’ equity
Junior subordinated debentures	85,881	95,643
Subordinated notes	114,074	98,127
Other liabilities	3,683	4,877
Total shareholders’ equity	1,514,983	1,232,883
Total liabilities and shareholders’ equity	$ 1,718,621	$ 1,431,530