Segment Information - Schedule of Segment Information (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Segment Reporting Information [Line Items]
Net interest income		$ 494,708	$ 418,351	$ 426,537
PCL	[1]	22,892	(24,448)	45,047
Noninterest income		205,144	221,910	274,593
Noninterest expense	[1]	603,213	489,296	466,301
Income Before Income Taxes		73,747	175,413	189,782
Income taxes		1,860	28,048	29,757
Net Income		71,887	147,365	160,025
Selected Financial Information
Total assets		18,015,478	17,595,636	16,551,840
Depreciation and amortization		39,882	45,813	41,325
General Banking [Member]
Segment Reporting Information [Line Items]
Net interest income		489,398	413,201	420,225
PCL	[1]	22,913	(24,439)	45,058
Noninterest income		116,350	137,874	197,691
Noninterest expense	[1]	531,397	421,561	401,810
Income Before Income Taxes		51,438	153,953	171,048
Income taxes		(3,683)	22,706	25,109
Net Income		55,121	131,247	145,939
Selected Financial Information
Total assets		17,710,673	17,275,438	16,226,358
Depreciation and amortization		38,909	44,776	40,351
Wealth Management [Member]
Segment Reporting Information [Line Items]
Net interest income		5,321	5,161	6,082
PCL		(21)	(9)	(11)
Noninterest income		35,072	35,420	31,634
Noninterest expense		32,873	31,721	30,318
Income Before Income Taxes		7,541	8,869	7,409
Income taxes		1,870	2,219	1,853
Net Income		5,671	6,650	5,556
Selected Financial Information
Total assets		214,313	232,997	242,429
Depreciation and amortization		288	269	274
Insurance [Member]
Segment Reporting Information [Line Items]
Net interest income		(11)	(11)	230
Noninterest income		53,722	48,616	45,268
Noninterest expense		38,943	36,014	34,173
Income Before Income Taxes		14,768	12,591	11,325
Income taxes		3,673	3,123	2,795
Net Income		11,095	9,468	8,530
Selected Financial Information
Total assets		90,492	87,201	83,053
Depreciation and amortization		$ 685	$ 768	$ 700

[1] During 2021, Trustmark reclassified its credit loss expense related to off-balance sheet credit exposures from noninterest expense to PCL, off-balance sheet credit exposures. Prior periods have been reclassified accordingly.