Pension and Other Postretirement Benefit Plans (Tables)

9 Months Ended

Sep. 30, 2020

Retirement Benefits [Abstract]

Schedule of Net Benefit Costs

The following table presents the components of the PNM Plans’ net periodic benefit cost:

	Three Months Ended September 30,
	Pension Plan				OPEB Plan				Executive Retirement Program
	2020		2019		2020		2019		2020		2019
	(In thousands)
Components of Net Periodic Benefit Cost
Service cost	$	—	$	—	$	9	$	13	$	—	$	—
Interest cost	4,985		6,294		613		829		123		163
Expected return on plan assets	(7,363)		(8,527)		(1,387)		(1,320)		—		—
Amortization of net loss	4,465		3,880		87		169		101		79
Amortization of prior service cost	(138)		(241)		—		(99)		—		—
Net Periodic Benefit Cost (Income)	$	1,949	$	1,406	$	(678)	$	(408)	$	224	$	242
	Nine Months Ended September 30,
	Pension Plan				OPEB Plan				Executive Retirement Program
	2020		2019		2020		2019		2020		2019
	(In thousands)
Components of Net Periodic Benefit Cost
Service cost	$	—	$	—	$	29	$	39	$	—	$	—
Interest cost	14,956		18,881		1,840		2,487		367		487
Expected return on plan assets	(22,089)		(25,577)		(4,161)		(3,956)		—		—
Amortization of net loss	13,395		11,639		261		507		302		237
Amortization of prior service cost	(415)		(724)		—		(297)		—		—
Net Periodic Benefit Cost (Income)	$	5,847	$	4,219	$	(2,031)	$	(1,220)	$	669	$	724

The following table presents the components of the TNMP Plans’ net periodic benefit cost:

	Three Months Ended September 30,
	Pension Plan				OPEB Plan				Executive Retirement Program
	2020		2019		2020		2019		2020		2019
	(In thousands)
Components of Net Periodic Benefit Cost
Service cost	$	—	$	—	$	12	$	12	$	—	$	—
Interest cost	545		672		93		113		6		7
Expected return on plan assets	(821)		(967)		(136)		(129)		—		—
Amortization of net (gain) loss	315		235		(81)		(111)		6		4
Amortization of prior service cost	—		—		—		—		—		—
Net Periodic Benefit Cost (Income)	$	39	$	(60)	$	(112)	$	(115)	$	12	$	11
	Nine Months Ended September 30,
	Pension Plan				OPEB Plan				Executive Retirement Program
	2020		2019		2020		2019		2020		2019
	(In thousands)
Components of Net Periodic Benefit Cost
Service cost	$	—	$	—	$	35	$	39	$	—	$	—
Interest cost	1,633		2,015		280		338		17		24
Expected return on plan assets	(2,463)		(2,901)		(404)		(387)		—		—
Amortization of net (gain) loss	944		706		(243)		(332)		18		11
Amortization of prior service cost	—		—		—		—		—		—
Net Periodic Benefit Cost (Income)	$	114	$	(180)	$	(332)	$	(342)	$	35	$	35