Defined Benefit and Other Postretirement Benefits (Tables)

6 Months Ended

Jun. 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 June 30,						Six Months Ended June 30,
	2024			2023			2024			2023
Service cost	$	10		$	13		$	20		$	26
Interest cost		61			73			123			146
Expected return on plan assets		(24	)		(27	)		(48	)		(53	)
Recognized net (gain) loss due to lump sum settlements		(13	)		—			(13	)		25
Net periodic benefit cost	$	34		$	59		$	82		$	144

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,
	2024		2023		2024		2023
Service cost	$	11	$	17	$	22	$	34
Interest cost		459		498		936		1,018
Amortization of prior service cost		27		27		55		55
Recognized net actuarial loss		84		69		179		146
Net periodic benefit cost	$	581	$	611	$	1,192	$	1,253