Interim Pension and Other Postretirement Benefit Plan Information

The components of our net periodic pension cost for our pension and other postretirement benefit plans for the three and six months ended March 31, 2019 and 2018 are presented in the following tables. Most of these costs are recoverable through our tariff rates. A portion of these costs is capitalized into our rate base or deferred as a regulatory asset or liability. The remaining costs are recorded as a component of operation and maintenance expense or other non-operating expense.



	Three Months Ended March 31
	Pension Benefits						Other Benefits
	2019			2018			2019			2018
	(In thousands)
Components of net periodic pension cost:
Service cost	$	4,045		$	4,575		$	2,703		$	3,019
Interest cost⁽¹⁾	6,801			6,433			2,958			2,727
Expected return on assets⁽¹⁾	(7,113		)	(6,916		)	(2,665		)	(2,001		)
Amortization of prior service cost (credit)⁽¹⁾	(58		)	(58		)	44			3
Amortization of actuarial (gain) loss⁽¹⁾	1,607			3,085			(2,044		)	(1,619		)
Settlements⁽¹⁾	—			2,415			—			—
Net periodic pension cost	$	5,282		$	9,534		$	996		$	2,129



	Six Months Ended March 31
	Pension Benefits						Other Benefits
	2019			2018			2019			2018
	(In thousands)
Components of net periodic pension cost:
Service cost	$	8,090		$	9,135		$	5,405		$	6,039
Interest cost⁽¹⁾	13,600			12,863			5,919			5,454
Expected return on assets⁽¹⁾	(14,226		)	(13,833		)	(5,330		)	(4,003		)
Amortization of prior service cost (credit)⁽¹⁾	(116		)	(116		)	87			6
Amortization of actuarial (gain) loss⁽¹⁾	3,215			6,174			(4,089		)	(3,237		)
Settlements⁽¹⁾	—			2,415			—			—
Net periodic pension cost	$	10,563		$	16,638		$	1,992		$	4,259


(1)	The components of net periodic cost other than the service cost component are included in the line item other non-operating expense in the condensed consolidated statement of comprehensive income or are capitalized on the condensed consolidated balance sheets as a regulatory asset or liability, as described in Note 2.