Defined Benefit and Other Postretirement Benefits (Tables)

3 Months Ended

Mar. 31, 2025

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 March 31,
	2025			2024
Service cost	$	9		$	10
Interest cost		69			62
Expected return on plan assets		(32	)		(24	)
Recognized net (gain) loss due to lump sum settlements		(50	)		—
Recognized net actuarial (gain) loss		(2	)		—
Net periodic benefit cost	$	(6	)	$	48

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 March 31,
	2025		2024
Service cost	$	4	$	11
Interest cost		495		477
Amortization of prior service cost		4		28
Recognized net actuarial loss		73		95
Net periodic benefit cost	$	576	$	611