Renasant Corporation (Parent Company Only) Condensed Financial Information - Statements of Cash Flows (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Operating activities
Net income	$ 175,892	$ 83,651	$ 167,596
Adjustments to reconcile net income to net cash provided by operating activities:
Increase in other assets	(20,812)	(59,224)	683
Increase in other liabilities	(42,920)	27,077	(12,249)
Net cash provided by operating activities	142,659	82,242	163,623
Investing activities
Purchases of securities available for sale	(2,107,934)	(515,657)	(492,018)
Other, net	3,663	1,446	917
Net cash used in investing activities	(660,003)	(1,265,548)	(505,910)
Financing activities
Cash paid for dividends	(50,017)	(50,134)	(50,901)
Repurchase of shares in connection with stock repurchase program	(21,315)	(24,569)	(62,944)
Repayment of long-term debt	(202,873)	(171)	(35,359)
Proceeds from long-term debt	197,061	98,266	150,000
Net cash provided by financing activities	1,762,106	1,401,579	188,106
Net increase (decrease) in cash and cash equivalents	1,244,762	218,273	(154,181)
Cash and cash equivalents at beginning of year	633,203	414,930	569,111
Cash and cash equivalents at end of year	1,877,965	633,203	414,930
Renasant Corporation
Operating activities
Net income	175,892	83,651	167,596
Adjustments to reconcile net income to net cash provided by operating activities:
Equity in undistributed net income of bank subsidiary	(108,674)	(13,322)	(46,684)
Amortization/depreciation (accretion)	891	692	(76)
Increase in other assets	(5,628)	(256)	(2,678)
Increase in other liabilities	6,952	10,932	10,872
Net cash provided by operating activities	69,433	81,697	129,030
Investing activities
Purchases of securities available for sale	0	(6,104)	0
Sales and maturities of securities and available for sale	5,100	541	42
Other, net	(100,000)	0	632
Net cash used in investing activities	(94,900)	(5,563)	674
Financing activities
Cash paid for dividends	(50,017)	(50,134)	(50,901)
Repurchase of shares in connection with stock repurchase program	(21,315)	(24,569)	(62,944)
Repayment of long-term debt	(45,000)	0	(30,973)
Proceeds from long-term debt	197,061	98,266	0
Net cash provided by financing activities	80,729	23,563	(144,818)
Net increase (decrease) in cash and cash equivalents	55,262	99,697	(15,114)
Cash and cash equivalents at beginning of year	129,164	29,467	44,581
Cash and cash equivalents at end of year	$ 184,426	$ 129,164	$ 29,467