Defined Benefit and Other Postretirement Benefits (Tables)

9 Months Ended

Sep. 30, 2024

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 September 30,						Nine Months Ended September 30,
	2024			2023			2024			2023
Service cost	$	10		$	13		$	30		$	39
Interest cost		62			73			185			219
Expected return on plan assets		(24	)		(27	)		(72	)		(80	)
Recognized net (gain) loss due to lump sum settlements		—			—			(13	)		25
Net periodic benefit cost	$	48		$	59		$	130		$	203

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 September 30,				Nine Months Ended September 30,
	2024		2023		2024		2023
Service cost	$	11	$	17	$	33	$	51
Interest cost		457		497		1,393		1,515
Amortization of prior service cost		28		28		83		83
Recognized net actuarial loss		84		70		263		216
Net periodic benefit cost	$	580	$	612	$	1,772	$	1,865