Defined Benefit and Other Postretirement Benefits (Tables)

9 Months Ended

Sep. 30, 2023

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,
	2023			2022			2023			2022
Service cost	$	13		$	28		$	39		$	86
Interest cost		73			48			219			144
Expected return on plan assets		(27	)		(30	)		(80	)		(90	)
Recognized net loss due to lump sum settlements		—			—			25			—
Recognized net actuarial loss		—			52			—			172
Net periodic benefit cost	$	59		$	98		$	203		$	312

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,
	2023		2022		2023		2022
Service cost	$	17	$	18	$	51	$	54
Interest cost		497		316		1,515		962
Amortization of prior service cost		28		28		83		83
Recognized net actuarial loss		70		243		216		742
Net periodic benefit cost	$	612	$	605	$	1,865	$	1,841