Revenue from Contracts with Customers - Summary of Noninterest Income Disaggregated by Reportable Operating Segment and Revenue Stream (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Revenue From Contract With Customer [Line Items]
Service charges on deposit accounts		$ 42,157	$ 33,246	$ 32,289
Bank card and other fees		36,105	34,662	31,022
Mortgage banking, net		28,306	63,750	125,822
Insurance commissions		53,721	48,511	45,176
Wealth management		35,013	35,190	31,625
Other, net		9,842	6,551	8,659
Total Noninterest Income		205,144	221,910	274,593
Topic 606 [Member]
Revenue From Contract With Customer [Line Items]
Service charges on deposit accounts		42,157	33,246	32,289
Bank card and other fees		31,521	30,935	27,428
Insurance commissions		53,721	48,511	45,176
Wealth management		35,013	35,190	31,625
Other, net		8,998	6,856	7,631
Total Noninterest Income		171,410	154,738	144,149
Not Topic 606 [Member]
Revenue From Contract With Customer [Line Items]
Bank card and other fees	[1]	4,584	3,727	3,594
Mortgage banking, net	[1]	28,306	63,750	125,822
Other, net	[1]	844	(305)	1,028
Total Noninterest Income	[1]	33,734	67,172	130,444
General Banking Segment [Member]
Revenue From Contract With Customer [Line Items]
Service charges on deposit accounts		42,073	33,169	32,213
Bank card and other fees		36,058	34,624	30,992
Mortgage banking, net		28,306	63,750	125,822
Wealth management		639	48	254
Other, net		9,274	6,283	8,410
Total Noninterest Income		116,350	137,874	197,691
General Banking Segment [Member] | Topic 606 [Member]
Revenue From Contract With Customer [Line Items]
Service charges on deposit accounts		42,073	33,169	32,213
Bank card and other fees		31,474	30,897	27,398
Wealth management		639	48	254
Other, net		8,469	6,621	7,432
Total Noninterest Income		82,655	70,735	67,297
General Banking Segment [Member] | Not Topic 606 [Member]
Revenue From Contract With Customer [Line Items]
Bank card and other fees	[1]	4,584	3,727	3,594
Mortgage banking, net	[1]	28,306	63,750	125,822
Other, net	[1]	805	(338)	978
Total Noninterest Income	[1]	33,695	67,139	130,394
Wealth Management Segment [Member]
Revenue From Contract With Customer [Line Items]
Service charges on deposit accounts		84	77	76
Bank card and other fees		47	38	30
Wealth management		34,374	35,142	31,371
Other, net		567	163	157
Total Noninterest Income		35,072	35,420	31,634
Wealth Management Segment [Member] | Topic 606 [Member]
Revenue From Contract With Customer [Line Items]
Service charges on deposit accounts		84	77	76
Bank card and other fees		47	38	30
Wealth management		34,374	35,142	31,371
Other, net		528	130	107
Total Noninterest Income		35,033	35,387	31,584
Wealth Management Segment [Member] | Not Topic 606 [Member]
Revenue From Contract With Customer [Line Items]
Other, net	[1]	39	33	50
Total Noninterest Income	[1]	39	33	50
Insurance Segment [Member]
Revenue From Contract With Customer [Line Items]
Insurance commissions		53,721	48,511	45,176
Other, net		1	105	92
Total Noninterest Income		53,722	48,616	45,268
Insurance Segment [Member] | Topic 606 [Member]
Revenue From Contract With Customer [Line Items]
Insurance commissions		53,721	48,511	45,176
Other, net		1	105	92
Total Noninterest Income		$ 53,722	$ 48,616	$ 45,268

[1] Noninterest income not in scope for FASB ASC Topic 606 includes customer derivatives revenue and miscellaneous credit card income within bank card and other fees; mortgage banking, net; amortization of tax credits, accretion of the FDIC indemnification asset, cash surrender value on various life insurance policies, earnings on Trustmark’s non-qualified deferred compensation plans, other partnership investments and rental income within other, net; and securities gains (losses), net.