Retirement Plans (Tables)

12 Months Ended

Dec. 31, 2020

Defined Benefit Plan Disclosure [Line Items]

Asset Allocation

The aggregate fair value of plan assets of the Company’s pension plans was $395,137,000 and $358,197,000 at December 31, 2020 and 2019 respectively. Pension assets were allocated among asset categories as follows:

	December 31,						Current Minimum, Target and Maximum
Asset Category	2020			2019			Allocation Policy
U.S. equity securities		53	%		53	%		30% — 50%— 70	%
International equity securities		20			19			0% — 20%— 30	%
Debt securities		25			26			15% — 30%— 55	%
Cash and cash equivalents		2			2			0% — 0%— 5	%
		100	%		100	%

Change in Benefit Obligation

The following table presents the change in benefit obligation and plan assets for the Company’s defined benefit plans and postretirement benefit plan (in thousands):

													Other Postretirement Benefits
	Pension Benefits												Postretirement Welfare Plan
	Pension Plans						SERP
	2020			2019			2020			2019			2020			2019
Change in benefit obligation
Benefit obligation at beginning of year	$	442,861		$	381,483		$	1,225		$	1,246		$	662		$	743
Service cost		7,671			7,364			—			—			—			—
Interest cost		15,630			16,493			40			52			22			31
Actuarial loss (gain)		58,851			49,478			55			72			84			(22	)
Gross benefits paid		(11,029	)		(11,957	)		(146	)		(145	)		(139	)		(90	)
Settlements		(5,290	)		—			—			—			—			—
Benefit obligation at end of year	$	508,694		$	442,861		$	1,174		$	1,225		$	629		$	662
Accumulated benefit obligation at end of year	$	479,999		$	417,981		$	1,174		$	1,225		$	629		$	662

Weighted-Average Assumption Used to Determine Benefit Obligation and Net Periodic Benefit Cost

Weighted-average assumption used to determine benefit obligation at end of year
Discount rate (a)		2.8% / 2.9	%		3.5	%	2.8	%	3.5	%	2.8	%	3.5	%
Rate of compensation increase	Service-based table			Service-based table			—		—		—		—
Health care cost trend rate
Initial rate		—			—		—		—		6.5	%	6.75	%
Ultimate rate		—			—		—		—		5.0	%	5.0	%
Years to ultimate		—			—		—		—		2025		2025

(a) The 2020 discount rate was 2.8% for the Kirby pension plan and 2.9% for the Higman pension plan.

Change in Plan Assets

Change in plan assets
Fair value of plan assets at beginning of year	$	358,197		$	303,151		$	—		$	—		$	—		$	—
Actual return on plan assets		51,024			63,939			—			—			—			—
Employer contribution		2,235			3,064			146			145			139			90
Gross benefits paid		(11,029	)		(11,957	)		(146	)		(145	)		(139	)		(90	)
Settlements		(5,290	)		—			—			—			—			—
Fair value of plan assets at end of year	$	395,137		$	358,197		$	—		$	—		$	—		$	—

Funded Status at End of Year

The following table presents the funded status and amounts recognized in the Company’s consolidated balance sheet for the Company’s defined benefit plans and postretirement benefit plan (in thousands):

													Other Postretirement Benefits
	Pension Benefits												Postretirement Welfare Plan
	Pension Plans						SERP
	2020			2019			2020			2019			2020			2019
Funded status at end of year
Fair value of plan assets	$	395,137		$	358,197		$	—		$	—		$	—		$	—
Benefit obligations		(508,694	)		(442,861	)		(1,174	)		(1,225	)		(629	)		(662	)
Funded status and amount recognized at end of year	$	(113,557	)	$	(84,664	)	$	(1,174	)	$	(1,225	)	$	(629	)	$	(662	)

Amounts Recognized in the Consolidated Balance Sheets

Amounts recognized in the consolidated balance sheets
Current liability	—		—		(159	)	(159	)	(58	)	(60	)
Long-term liability	(113,557	)	(84,664	)	(1,015	)	(1,066	)	(571	)	(602	)

Amounts Recognized in Accumulated Other Comprehensive Income

Amounts recognized in accumulated other comprehensive income
Net actuarial loss (gain)	$	81,376	$	52,160	$	480	$	460	$	(3,189	)	$	(3,795	)
Prior service cost (credit)		—		—		—		—		—			—
Accumulated other compensation income	$	81,376	$	52,160	$	480	$	460	$	(3,189	)	$	(3,795	)

Expected Cash Flows for the Defined Benefit Plans and Postretirement Benefit Plan

The following table presents the expected cash flows for the Company’s defined benefit plans and postretirement benefit plan (in thousands):

									Other Postretirement Benefits
	Pension Benefits								Postretirement Welfare Plan
	Pension Plans				SERP
	2020		2019		2020		2019		2020		2019
Expected employer contributions
First year	$	2,385	$	2,407	$	—	$	—	$	—	$	—
Expected benefit payments (gross)
Year one	$	13,902	$	12,063	$	162	$	162	$	59	$	61
Year two		14,902		13,123		136		158		49		62
Year three		16,123		14,300		110		133		48		51
Year four		17,284		15,572		106		107		47		51
Year five		18,315		16,857		101		103		46		49
Next five years		106,400		100,587		406		426		202		220

Pension Benefits [Member]

Defined Benefit Plan Disclosure [Line Items]

Net Periodic Benefit Cost

The components of net periodic benefit cost and other changes in plan assets and benefit obligations recognized in other comprehensive income for the Company’s defined benefit plans were as follows (in thousands):

	Pension Benefits
	Pension Plans									SERP
	2020			2019			2018			2020			2019			2018
Components of net periodic benefit cost
Service cost	$	7,671		$	7,364		$	7,622		$	—		$	—		$	—
Interest cost		15,630			16,493			15,499			40			52			49
Expected return on plan assets		(23,790	)		(20,956	)		(22,406	)		—			—			—
Amortization of actuarial loss		2,399			1,438			2,890			35			28			23
Net periodic benefit cost		1,910			4,339			3,605			75			80			72
Other changes in plan assets and benefit obligations recognized in other comprehensive income
Current year actuarial loss (gain)		31,616			6,497			(7,396	)		55			73			(70	)
Recognition of actuarial loss		(2,399	)		(1,438	)		(2,890	)		(35	)		(28	)		(23	)
Total recognized in other comprehensive income		29,217			5,059			(10,286	)		20			45			(93	)
Total recognized in net periodic benefit cost and other comprehensive income	$	31,127		$	9,398		$	(6,681	)	$	95		$	125		$	(21	)
Weighted average assumptions used to determine net periodic benefit cost
Discount rate (a)		3.5% / 3.10	%		4.4	%		3.7	%		3.5	%		4.4	%		3.7	%
Expected long-term rate of return on plan assets		6.75	%		7.0	%		7.0	%		—			—			—
Rate of compensation increase	Service- based table			Service- based table			Service- based table				—			—			—

(a) The 2020 discount rate for benefit cost is 3.5% for the Kirby pension plan and 3.1% for the Higman pension plan. The 2018 discount rate for benefit cost for the Higman pension plan was changed from 4.13% as of February 14, 2018 and 4.02% as of March 31, 2018 to 4.40% as of December 31, 2018.

Other Postretirement Benefits [Member]

Defined Benefit Plan Disclosure [Line Items]

Net Periodic Benefit Cost

The components of net periodic benefit cost and other changes in benefit obligations recognized in other comprehensive income for the Company’s postretirement benefit plan were as follows (in thousands):

	Other Postretirement Benefits
	Postretirement Welfare Plan
	2020			2019			2018
Components of net periodic benefit cost
Interest cost	$	22		$	31		$	24
Amortization of actuarial gain		(522	)		(540	)		(596	)
Net periodic benefit cost		(500	)		(509	)		(572	)
Other changes in benefit obligations recognized in other comprehensive income
Current year actuarial loss (gain)		84			(22	)		144
Recognition of actuarial gain		522			540			596
Total recognized in other comprehensive income		606			518			740
Total recognized in net periodic benefit cost and other comprehensive income	$	106		$	9		$	168
Weighted average assumptions used to determine net periodic benefit cost
Discount rate		3.5	%		4.4	%		3.7	%
Health care cost trend rate:
Initial rate		6.75	%		7.0	%		7.0	%
Ultimate rate		5.0	%		5.0	%		5.0	%
Years to ultimate		2025			2025			2022