Interim Pension and Other Postretirement Benefit Plan Information (Table)

3 Months Ended

Dec. 31, 2021

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 months ended December 31, 2021 and 2020 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 December 31
	Pension Benefits				Other Benefits
	2021		2020		2021		2020
	(In thousands)
Components of net periodic pension cost:
Service cost	$	4,323	$	4,612	$	2,559	$	4,306
Interest cost (1)	5,063		5,028		2,683		2,660
Expected return on assets (1)	(7,383)		(6,978)		(3,312)		(2,614)
Amortization of prior service cost (credit) (1)	(58)		(58)		(3,309)		43
Amortization of actuarial (gain) loss (1)	1,951		3,172		—		—
Net periodic pension cost	$	3,896	$	5,776	$	(1,379)	$	4,395

(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.