Pension and Other Postretirement Benefit Plans (Tables)

3 Months Ended

Mar. 31, 2019

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 March 31,
	Pension Plan						OPEB Plan						Executive Retirement Program
	2019			2018			2019			2018			2019		2018
	(In thousands)
Components of Net Periodic Benefit Cost
Service cost	$	—		$	—		$	13		$	21		$	—	$	—
Interest cost	6,294			6,068			829			860			162		155
Expected return on plan assets	(8,527		)	(8,672		)	(1,318		)	(1,353		)	—		—
Amortization of net (gain) loss	3,880			4,087			169			588			79		90
Amortization of prior service cost	(241		)	(241		)	(99		)	(416		)	—		—
Net periodic benefit cost	$	1,406		$	1,242		$	(406	)	$	(300	)	$	241	$	245

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

	Three Months Ended March 31,
	Pension Plan						OPEB Plan						Executive Retirement Program
	2019			2018			2019			2018			2019		2018
	(In thousands)
Components of Net Periodic Benefit Cost
Service cost	$	—		$	—		$	13		$	33		$	—	$	—
Interest cost	672			656			113			119			8		7
Expected return on plan assets	(967		)	(991		)	(129		)	(135		)	—		—
Amortization of net (gain) loss	235			272			(110		)	(56		)	4		4
Amortization of prior service cost	—			—			—			—			—		—
Net Periodic Benefit Cost	$	(60	)	$	(63	)	$	(113	)	$	(39	)	$	12	$	11