Renasant Corporation (Parent Company Only) Condensed Financial Information - Statements of Income (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income
Other dividends									$ 1,189	$ 5,892	$ 3,076
Total noninterest income	$ 62,864	$ 70,928	$ 64,170	$ 37,570	$ 37,456	$ 37,953	$ 41,960	$ 35,885	235,532	153,254	143,961
Expenses	13,799	15,792	18,173	23,571	24,263	25,651	25,062	23,947	71,335	98,923	65,329
Income before income tax benefit and equity in undistributed net income of bank subsidiary	38,339	37,604	24,767	2,781	47,839	48,578	60,570	58,700	103,491	215,687	188,647
Income tax benefit	6,818	7,612	4,637	773	9,424	11,132	13,945	13,590	19,840	48,091	41,727
Net income	$ 31,521	$ 29,992	$ 20,130	$ 2,008	$ 38,415	$ 37,446	$ 46,625	$ 45,110	83,651	167,596	146,920
Renasant Corporation
Income
Dividends from bank subsidiary									81,443	132,563	53,381
Interest income from bank subsidiary									9	9	8
Other dividends									93	175	137
Other income									74	138	121
Total noninterest income									81,619	132,885	53,647
Expenses									15,179	16,050	13,869
Income before income tax benefit and equity in undistributed net income of bank subsidiary									66,440	116,835	39,778
Income tax benefit									(3,889)	(4,077)	(3,523)
Equity in undistributed net income of bank subsidiary									13,322	46,684	103,619
Net income									$ 83,651	$ 167,596	$ 146,920