Defined Benefit and Other Postretirement Benefits (Tables)

6 Months Ended

Jun. 30, 2026

Trustmark Capital Accumulation Plan [Member]

Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items]

Net Periodic Benefit Cost

The following table presents information regarding the net periodic benefit cost for the Continuing Plan for the periods presented ($ in thousands):


		Three Months Ended June 30,								Six Months Ended June 30,
		2026				2025				2026				2025
Service cost		$	7			$	9			$	14			$	18
Interest cost			50				69				100				138
Expected return on plan assets			(19	)			(31	)			(38	)			(63	)
Recognized net (gain) loss due to lump sum settlements			(31	)			—				(31	)			(50	)
Recognized net actuarial (gain) loss			(3	)			(2	)			(6	)			(4	)
Net periodic benefit cost		$	4			$	45			$	39			$	39

Supplemental Retirement Plan [Member]

Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items]

Net Periodic Benefit Cost

The following table presents information regarding the net periodic benefit cost for Trustmark’s nonqualified supplemental retirement plans for the periods presented ($ in thousands):


		Three Months Ended June 30,								Six Months Ended June 30,
		2026				2025				2026				2025
Service cost		$	2			$	4			$	4			$	8
Interest cost			435				475				886				970
Amortization of prior service cost			—				3				—				7
Recognized net actuarial loss			76				63				164				136
Net periodic benefit cost		$	513			$	545			$	1,054			$	1,121