Postretirement Benefits (Tables)

3 Months Ended

Mar. 31, 2021

Retirement Benefits [Abstract]

Pension Assets by Component at Fair Value

Pension Assets by Component at March 31, 2021

	Fair Value Determined by:
	Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)		Total Amount		% to Total
Corporate bonds:
Financial	$	—	$	54,420	$	—	$	54,420	10
Utilities	—		42,598		—		42,598		8
Energy	—		22,015		—		22,015		4
Other corporates	—		90,605		—		90,605		17
Total corporate bonds	—		209,638		—		209,638		39
Exchange traded fund(1)	259,872		—		—		259,872		49
Other bonds	—		244		—		244		—
Guaranteed annuity contract(2)	—		30,253		—		30,253		6
Short-term investments	6,651		—		—		6,651		1
Other	8,419		—		—		8,419		2
	$	274,942	$	240,135	$	—	515,077		97
Other long-term investments(3)							15,608		3
Total pension assets							$	530,685	100

(1)A fund including marketable securities that mirror the S&P 500 index.

(2)Representing a guaranteed annuity contract issued by Globe Life Inc.'s subsidiary, American Income Life Insurance Company, to fund the obligations of the American Income Life Insurance Company Non-Exempt Employees Defined Benefit Pension Plan ("American Income Pension Plan").

(3)Included in other long-term investments is an investment fund that reports the Pension Plan's pro-rata share of the limited partnership's net asset value per share or its equivalent (NAV), as a practical expedient for fair value. The Pension Plan owns less than 1% of the investment fund. As of March 31, 2021, the expected term of the investment fund is approximately 4 years and the commitment of the investment is fully funded. The investment is non-redeemable.

Pension Assets by Component at December 31, 2020

	Fair Value Determined by:
	Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)		Total Amount		% to Total
Corporate bonds:
Financial	$	—	$	52,252	$	—	$	52,252	10
Utilities	—		45,888		—		45,888		9
Energy	—		22,480		—		22,480		4
Other corporates	—		88,983		—		88,983		17
Total corporate bonds	—		209,603		—		209,603		40
Exchange traded fund(1)	245,170		—		—		245,170		46
Other bonds	—		258		—		258		—
Guaranteed annuity contract(2)	—		30,119		—		30,119		6
Short-term investments	20,960		—		—		20,960		4
Other	7,109		—		—		7,109		1
	$	273,239	$	239,980	$	—	513,219		97
Other long-term investments(3)							16,313		3
Total pension assets							$	529,532	100

(1)A fund including marketable securities that mirror the S&P 500 index.

(2)Representing a guaranteed annuity contract issued by Globe Life Inc.'s subsidiary, American Income Life Insurance Company, to fund the obligations of the American Income Pension Plan.

(3)Included in other long-term investments is an investment fund that reports the Pension Plan's pro-rata share of the limited partnership's net asset value per share or its equivalent (NAV), as a practical expedient for fair value. The Pension Plan owns approximately 1% of the investment fund. As of December 31, 2020, the expected term of the investment fund is approximately 4 years and the commitment of the investment is fully funded. The investment is non-redeemable.

Information Regarding the SERP

The following table includes information regarding the SERP.

	Three Months Ended March 31,
	2021		2020
Premiums paid for insurance coverage	$	443	$	443
	March 31, 2021		December 31, 2020
Total investments:
Company owned life insurance	$	52,138	$	51,361
Exchange traded funds	74,711		75,390
	$	126,849	$	126,751

Pension Liability

The following table presents liabilities for the defined benefit pension plans and SERP at March 31, 2021 and December 31, 2020.

	March 31, 2021		December 31, 2020
Defined benefit pension	$	673,114	$	667,753
SERP	95,631		95,560
Pension benefit obligation	$	768,745	$	763,313

Net Periodic Benefit Cost

The following table presents the net periodic benefit costs for the defined benefit pension plans and SERP by expense components for the three months ended March 31, 2021 and 2020.

Components of Net Periodic Benefit Cost

	Three Months Ended March 31,
	2021		2020
Service cost	$	7,918	$	6,116
Interest cost	5,467		5,651
Expected return on assets	(8,083)		(7,390)
Amortization:
Prior service cost	158		158
Actuarial (gain) loss	4,985		3,924
Net periodic benefit cost	$	10,445	$	8,459