Renasant Corporation (Parent Company Only) Condensed Financial Information - Statements of Income (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income
Other dividends									$ 5,892	$ 3,076	$ 2,314
Total noninterest income	$ 37,456	$ 37,953	$ 41,960	$ 35,885	$ 36,374	$ 38,053	$ 35,581	$ 33,953	153,254	143,961	132,140
Expenses	24,263	25,651	25,062	23,947	21,648	18,356	14,185	11,140	98,923	65,329	37,853
Income before income tax benefit and equity in undistributed net income of bank subsidiary	47,839	48,578	60,570	58,700	57,518	40,496	47,134	43,499	215,687	188,647	159,869
Income tax benefit	9,424	11,132	13,945	13,590	13,098	8,532	10,424	9,673	48,091	41,727	67,681
Net income	$ 38,415	$ 37,446	$ 46,625	$ 45,110	$ 44,420	$ 31,964	$ 36,710	$ 33,826	167,596	146,920	92,188
Renasant Corporation
Income
Dividends from bank subsidiary									132,563	53,381	34,416
Interest income from bank subsidiary									9	8	8
Other dividends									175	137	94
Other income									138	121	588
Total noninterest income									132,885	53,647	35,106
Expenses									16,050	13,869	12,649
Income before income tax benefit and equity in undistributed net income of bank subsidiary									116,835	39,778	22,457
Income tax benefit									(4,077)	(3,523)	(3,761)
Equity in undistributed net income of bank subsidiary									46,684	103,619	65,970
Net income									$ 167,596	$ 146,920	$ 92,188