Defined Benefit and Other Postretirement Benefits (Tables)

12 Months Ended

Dec. 31, 2019

Trustmark Capital Accumulation Plan [Member]

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

Plan Benefit Obligation, Plan Assets and Funded Status of the Plan

The following tables present information regarding the benefit obligation, plan assets, funded status, amounts recognized in accumulated other comprehensive loss, net periodic benefit cost and other statistical disclosures for the Continuing Plan and the Plan for the periods presented ($ in thousands):

	December 31,
	2019			2018
Change in benefit obligation:
Benefit obligation, beginning of year	$	9,179		$	10,102
Service cost		211			277
Interest cost		361			332
Actuarial (gain) loss		875			(827	)
Benefits paid		(1,566	)		(705	)
Benefit obligation, end of year	$	9,060		$	9,179
Change in plan assets:
Fair value of plan assets, beginning of year	$	3,954		$	4,596
Actual return on plan assets		668			(314	)
Employer contributions		387			377
Benefit payments		(1,566	)		(705	)
Fair value of plan assets, end of year	$	3,443		$	3,954
Funded status at end of year - net liability	$	(5,617	)	$	(5,225	)
Amounts recognized in accumulated other comprehensive loss:
Net loss - amount recognized	$	1,893		$	2,170

Net Periodic Benefit Cost

	Years Ended December 31,
	2019			2018			2017
Net periodic benefit cost:
Service cost	$	211		$	277		$	253
Interest cost		361			332			1,461
Expected return on plan assets		(202	)		(227	)		(317	)
Recognized net loss due to defined benefit plan termination		—			—			17,662
Recognized net loss due to lump sum settlements		312			161			—
Recognized net actuarial loss		373			571			1,414
Net periodic benefit cost	$	1,055		$	1,114		$	20,473
Other changes in plan assets and benefit obligation recognized in other    comprehensive income (loss), before taxes:
Net loss - Total recognized in other comprehensive income (loss)	$	(277	)	$	(1,017	)	$	(18,168	)
Total recognized in net periodic benefit cost and other comprehensive    income (loss)	$	778		$	97		$	2,305
Weighted-average assumptions as of end of year:
Discount rate for benefit obligation		2.84	%		3.97	%		3.32	%
Discount rate for net periodic benefit cost		3.97	%		3.32	%		3.71	%
Expected long-term return on plan assets		5.00	%		5.00	%		5.00	%

Weighted-Average Asset Allocation

The weighted-average asset allocations by asset category are presented below for the Continuing Plan at December 31, 2019 and 2018.  

	December 31,
	2019			2018
Money market fund		2.0	%		8.0	%
Exchange traded funds:
Equity securities		46.0	%		52.0	%
Fixed income		41.0	%		29.0	%
International		11.0	%		11.0	%
Total		100.0	%		100.0	%

Plan Assets Measured at Fair Value

The following table sets forth by level, within the fair value hierarchy, the Continuing Plan’s assets measured at fair value at December 31, 2019 and 2018 ($ in thousands):

	December 31, 2019
	Total		Level 1		Level 2		Level 3
Money market fund	$	51	$	51	$	—	$	—
Exchange traded funds:
Equity securities		1,592		1,592		—		—
Fixed income		1,417		1,417		—		—
International		383		383		—		—
Total assets at fair value	$	3,443	$	3,443	$	—	$	—

	December 31, 2018
	Total		Level 1		Level 2		Level 3
Money market fund	$	304	$	304	$	—	$	—
Exchange traded funds:
Equity securities		2,044		2,044		—		—
Fixed income		1,162		1,162		—		—
International		444		444		—		—
Total assets at fair value	$	3,954	$	3,954	$	—	$	—

Estimated Future Benefit Payments and Other Disclosures

The following table presents the expected benefit payments, which reflect expected future service, for the Continuing Plan ($ in thousands):

Year	Amount
2020	$	1,147
2021		1,056
2022		873
2023		1,220
2024		997
2025 - 2029		2,443

Supplemental Retirement Plan [Member]

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

Plan Benefit Obligation, Plan Assets and Funded Status of the Plan

The following tables present information regarding the benefit obligation, plan assets, funded status, amounts recognized in accumulated other comprehensive loss, net periodic benefit cost and other statistical disclosures for Trustmark’s nonqualified supplemental retirement plans for the periods presented ($ in thousands):

	December 31,
	2019			2018
Change in benefit obligation:
Benefit obligation, beginning of year	$	53,257		$	57,930
Service cost		109			116
Interest cost		2,044			1,865
Actuarial (gain) loss		5,498			(3,228	)
Benefits paid		(3,426	)		(3,426	)
Benefit obligation, end of year	$	57,482		$	53,257
Change in plan assets:
Fair value of plan assets, beginning of year	$	—		$	—
Employer contributions		3,426			3,426
Benefit payments		(3,426	)		(3,426	)
Fair value of plan assets, end of year	$	—		$	—
Funded status at end of year - net liability	$	(57,482	)	$	(53,257	)
Amounts recognized in accumulated other comprehensive loss:
Net loss	$	18,275		$	13,403
Prior service cost		609			859
Amounts recognized	$	18,884		$	14,262

Net Periodic Benefit Cost

	Years Ended December 31,
	2019			2018			2017
Net periodic benefit cost:
Service cost	$	109		$	116		$	141
Interest cost		2,044			1,865			2,103
Amortization of prior service cost		250			250			250
Recognized net actuarial loss		627			884			866
Net periodic benefit cost	$	3,030		$	3,115		$	3,360
Other changes in plan assets and benefit obligation recognized in other    comprehensive income (loss), before taxes:
Net (gain) loss	$	4,872		$	(4,111	)	$	(224	)
Amortization of prior service cost		(250	)		(250	)		(250	)
Total recognized in other comprehensive income (loss)	$	4,622		$	(4,361	)	$	(474	)
Total recognized in net periodic benefit cost and other comprehensive    income (loss)	$	7,652		$	(1,246	)	$	2,886
Weighted-average assumptions as of end of year:
Discount rate for benefit obligation		2.84	%		3.97	%		3.32	%
Discount rate for net periodic benefit cost		3.97	%		3.32	%		3.71	%

Estimated Future Benefit Payments and Other Disclosures

The following table presents the expected benefits payments for Trustmark’s supplemental retirement plans ($ in thousands):

Year	Amount
2020	$	3,963
2021		4,051
2022		4,284
2023		4,124
2024		4,144
2025 - 2029		17,840