Revenue from Contracts with Customers - Summary of Noninterest Income Disaggregated by Reportable Operating Segment and Revenue Stream (Details) - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2022	Mar. 31, 2021
Revenue From Contract With Customer [Line Items]
Service charges on deposit accounts		$ 9,451	$ 7,356
Bank card and other fees		8,442	9,472
Mortgage banking, net		9,873	20,804
Insurance commissions		14,089	12,445
Wealth management		9,054	8,416
Other, net		3,206	2,090
Total Noninterest Income		54,115	60,583
Topic 606 [Member]
Revenue From Contract With Customer [Line Items]
Service charges on deposit accounts		9,451	7,356
Bank card and other fees		7,427	7,192
Insurance commissions		14,089	12,445
Wealth management		9,054	8,416
Other, net		2,542	1,443
Total Noninterest Income		42,563	36,852
Not Topic 606 [Member]
Revenue From Contract With Customer [Line Items]
Bank card and other fees	[1]	1,015	2,280
Mortgage banking, net	[1]	9,873	20,804
Other, net	[1]	664	647
Total Noninterest Income	[1]	11,552	23,731
General Banking Segment [Member]
Revenue From Contract With Customer [Line Items]
Service charges on deposit accounts		9,431	7,338
Bank card and other fees		8,432	9,464
Mortgage banking, net		9,873	20,804
Wealth management		24	18
Other, net		3,175	2,028
Total Noninterest Income		30,935	39,652
General Banking Segment [Member] | Topic 606 [Member]
Revenue From Contract With Customer [Line Items]
Service charges on deposit accounts		9,431	7,338
Bank card and other fees		7,417	7,184
Wealth management		24	18
Other, net		2,518	1,388
Total Noninterest Income		19,390	15,928
General Banking Segment [Member] | Not Topic 606 [Member]
Revenue From Contract With Customer [Line Items]
Bank card and other fees	[1]	1,015	2,280
Mortgage banking, net	[1]	9,873	20,804
Other, net	[1]	657	640
Total Noninterest Income	[1]	11,545	23,724
Wealth Management Segment [Member]
Revenue From Contract With Customer [Line Items]
Service charges on deposit accounts		20	18
Bank card and other fees		10	8
Wealth management		9,030	8,398
Other, net		39	39
Total Noninterest Income		9,099	8,463
Wealth Management Segment [Member] | Topic 606 [Member]
Revenue From Contract With Customer [Line Items]
Service charges on deposit accounts		20	18
Bank card and other fees		10	8
Wealth management		9,030	8,398
Other, net		32	32
Total Noninterest Income		9,092	8,456
Wealth Management Segment [Member] | Not Topic 606 [Member]
Revenue From Contract With Customer [Line Items]
Other, net	[1]	7	7
Total Noninterest Income	[1]	7	7
Insurance Segment [Member]
Revenue From Contract With Customer [Line Items]
Insurance commissions		14,089	12,445
Other, net		(8)	23
Total Noninterest Income		14,081	12,468
Insurance Segment [Member] | Topic 606 [Member]
Revenue From Contract With Customer [Line Items]
Insurance commissions		14,089	12,445
Other, net		(8)	23
Total Noninterest Income		$ 14,081	$ 12,468

[1] Noninterest income 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, 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 security gains (losses), net.