Defined Benefit and Other Postretirement Benefits (Tables)

3 Months Ended

Mar. 31, 2017

Trustmark Capital Accumulation Plan [Member]

Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items]

Net Periodic Benefit Cost for Plan and Spin-Off Plan

The following table presents information regarding the net periodic benefit cost for the Plan and the Spin-Off Plan for the periods presented ($ in thousands):

	Three Months Ended March 31,
	2017			2016
Service cost	$	63		$	108
Interest cost		665			830
Expected return on plan assets		(108	)		(1,022	)
Recognized net loss due to lump sum settlements		—			423
Recognized net actuarial loss		565			661
Net periodic benefit cost	$	1,185		$	1,000

Supplemental Retirement Plan [Member]

Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items]

Net Periodic Benefit Cost for Plan and Spin-Off Plan

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,
	2017		2016
Service cost	$	35	$	74
Interest cost		561		546
Amortization of prior service cost		63		63
Recognized net actuarial loss		222		221
Net periodic benefit cost	$	881	$	904