v3.26.1
Defined Benefit and Other Postretirement Benefits (Tables)
3 Months Ended
Mar. 31, 2026
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 March 31,

 

 

 

2026

 

 

2025

 

Service cost

 

$

7

 

 

$

9

 

Interest cost

 

 

50

 

 

 

69

 

Expected return on plan assets

 

 

(19

)

 

 

(32

)

Recognized net (gain) loss due to lump sum settlements

 

 

 

 

 

(50

)

Recognized net actuarial (gain) loss

 

 

(3

)

 

 

(2

)

Net periodic benefit cost

 

$

35

 

 

$

(6

)

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 March 31,

 

 

 

2026

 

 

2025

 

Service cost

 

$

2

 

 

$

4

 

Interest cost

 

 

451

 

 

 

495

 

Amortization of prior service cost

 

 

 

 

 

4

 

Recognized net actuarial loss

 

 

88

 

 

 

73

 

Net periodic benefit cost

 

$

541

 

 

$

576