Parent Company Only Financial Information - Additional Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Condensed Financial Statements Captions [Line Items]
Income taxes paid	$ 15,259,000	$ 46,648,000	$ 24,809,000
Trustmark Corp (Parent Company Only) [Member]
Condensed Financial Statements Captions [Line Items]
Income taxes paid	15,300,000	46,600,000	24,800,000
Interest paid	$ 4,600,000	0
Interest received		$ 0	$ 482,000