Defined Benefit and Other Postretirement Benefits (Tables)

9 Months Ended

Sep. 30, 2021

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,
	2021			2020			2021			2020
Service cost	$	63		$	64		$	189		$	191
Interest cost		43			60			129			181
Expected return on plan assets		(33	)		(39	)		(98	)		(116	)
Recognized net loss due to lump sum settlements		183			40			183			80
Recognized net actuarial loss		149			82			446			245
Net periodic benefit cost	$	405		$	207		$	849		$	581

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,
	2021		2020		2021		2020
Service cost	$	19	$	19	$	57	$	58
Interest cost		277		388		847		1,189
Amortization of prior service cost		28		37		84		112
Recognized net actuarial loss		295		237		896		719
Net periodic benefit cost	$	619	$	681	$	1,884	$	2,078