Interim Pension and Other Postretirement Benefit Plan Information (Table)

9 Months Ended

Jun. 30, 2022

Retirement Benefits, Description [Abstract]

Schedule of Net Benefit Costs

The components of our net periodic pension cost for our pension and other postretirement benefit plans for the three and nine months ended June 30, 2022 and 2021 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 June 30
	Pension Benefits				Other Benefits
	2022		2021		2022		2021
	(In thousands)
Components of net periodic pension cost:
Service cost	$	4,323	$	4,609	$	2,559	$	4,305
Interest cost (1)	5,063		5,016		2,683		2,661
Expected return on assets (1)	(7,383)		(6,978)		(3,312)		(2,613)
Amortization of prior service cost (credit) (1)	(58)		(58)		(3,308)		44
Amortization of actuarial (gain) loss (1)	1,951		3,062		—		—
Settlements(1)	—		8,999		—		—
Net periodic pension cost	$	3,896	$	14,650	$	(1,378)	$	4,397

	Nine Months Ended June 30
	Pension Benefits				Other Benefits
	2022		2021		2022		2021
	(In thousands)
Components of net periodic pension cost:
Service cost	$	12,970	$	13,834	$	7,676	$	12,917
Interest cost (1)	15,190		15,072		8,050		7,981
Expected return on assets (1)	(22,149)		(20,934)		(9,937)		(7,841)
Amortization of prior service cost (credit) (1)	(174)		(174)		(9,925)		130
Amortization of actuarial (gain) loss (1)	5,853		9,405		—		—
Settlements(1)	—		8,999		—		—
Net periodic pension cost	$	11,690	$	26,202	$	(4,136)	$	13,187

(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 statements of comprehensive income or are capitalized on the condensed consolidated balance sheets as a regulatory asset or liability, as described in Note 2 to the consolidated financial statements in our Annual Report on Form 10-K for the fiscal year ended September 30, 2021.