Revenue from Contracts with Customers - Summary of Noninterest Income (Loss) Disaggregated by Reportable Operating Segment and Revenue Stream (Details) - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2025	Mar. 31, 2024
Revenue From Contract With Customer [Line Items]
Service charges on deposit accounts		$ 10,636	$ 10,958
Bank card and other fees		7,664	7,428
Mortgage banking, net		8,771	8,915
Wealth management		9,543	8,952
Other, net		5,970	3,102
Total Noninterest Income (loss)		42,584	39,355
Topic 606 [Member]
Revenue From Contract With Customer [Line Items]
Service charges on deposit accounts		10,636	10,958
Bank card and other fees		7,419	7,228
Wealth management		9,543	8,952
Other, net		5,465	3,390
Total Noninterest Income (loss)		33,063	30,528
Not Topic 606 [Member]
Revenue From Contract With Customer [Line Items]
Bank card and other fees	[1]	245	200
Mortgage banking, net	[1]	8,771	8,915
Other, net	[1]	505	(288)
Total Noninterest Income (loss)	[1]	9,521	8,827
General Banking Segment [Member]
Revenue From Contract With Customer [Line Items]
Service charges on deposit accounts		10,615	10,936
Bank card and other fees		7,625	7,392
Mortgage banking, net		8,771	8,915
Wealth management		181	189
Other, net		5,822	2,966
Total Noninterest Income (loss)		33,014	30,398
General Banking Segment [Member] | Topic 606 [Member]
Revenue From Contract With Customer [Line Items]
Service charges on deposit accounts		10,615	10,936
Bank card and other fees		7,380	7,192
Wealth management		181	189
Other, net		5,413	3,348
Total Noninterest Income (loss)		23,589	21,665
General Banking Segment [Member] | Not Topic 606 [Member]
Revenue From Contract With Customer [Line Items]
Bank card and other fees	[1]	245	200
Mortgage banking, net	[1]	8,771	8,915
Other, net	[1]	409	(382)
Total Noninterest Income (loss)	[1]	9,425	8,733
Wealth Management Segment [Member]
Revenue From Contract With Customer [Line Items]
Service charges on deposit accounts		21	22
Bank card and other fees		39	36
Mortgage banking, net		0	0
Wealth management		9,362	8,763
Other, net		148	136
Total Noninterest Income (loss)		9,570	8,957
Wealth Management Segment [Member] | Topic 606 [Member]
Revenue From Contract With Customer [Line Items]
Service charges on deposit accounts		21	22
Bank card and other fees		39	36
Wealth management		9,362	8,763
Other, net		52	42
Total Noninterest Income (loss)		9,474	8,863
Wealth Management Segment [Member] | Not Topic 606 [Member]
Revenue From Contract With Customer [Line Items]
Other, net	[1]	96	94
Total Noninterest Income (loss)	[1]	$ 96	$ 94

[1] Noninterest income (loss) not in scope for FASB ASC Topic 606 includes customer derivatives revenue and miscellaneous credit card fee income within bank card and other fees; mortgage banking, net; amortization of tax credits, 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.