EMPLOYEE BENEFIT PLANS (Notes)

9 Months Ended

Sep. 30, 2022

Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Abstract]

Employee Benefit Plans (Notes)

EMPLOYEE BENEFIT PLANS

The following tables set forth the components of net periodic benefit cost for our pension and other postemployment benefit plans for the periods indicated:

	Pension Benefits
	Three Months Ended				Nine Months Ended
	September 30,				September 30,
	2022		2021		2022		2021
	(Thousands of dollars)
Components of net periodic benefit cost (credit)
Service cost	$	2,341	$	3,453	$	8,027	$	10,359
Interest cost	9,654		7,365		26,495		22,095
Expected return on assets	(14,642)		(15,596)		(43,887)		(46,788)
Amortization of unrecognized prior service cost	93		—		155		—
Amortization of net loss	2,224		11,381		14,569		34,143
Net periodic benefit cost (credit)	$	(330)	$	6,603	$	5,359	$	19,809

	Other Postemployment Benefits
	Three Months Ended				Nine Months Ended
	September 30,				September 30,
	2022		2021		2022		2021
	(Thousands of dollars)
Components of net periodic benefit cost (credit)
Service cost	$	318	$	397	$	954	$	1,191
Interest cost	1,612		1,563		4,836		4,689
Expected return on assets	(3,295)		(4,202)		(9,885)		(12,606)
Amortization of unrecognized prior service cost (credit)	10		(70)		30		(210)
Amortization of net loss	54		93		162		279
Net periodic benefit cost (credit)	$	(1,301)	$	(2,219)	$	(3,903)	$	(6,657)

We recover qualified pension benefit plan and other postemployment benefit plan costs through rates charged to our customers. Certain regulatory authorities require that the recovery of these costs be based on specific guidelines. The difference between these regulatory-based amounts and the periodic benefit cost calculated pursuant to GAAP is deferred as a regulatory asset or liability and amortized to expense over periods in which this difference will be recovered in rates, as authorized by the

applicable regulatory authorities. For the nine months ended September 30, 2022, regulatory deferrals related to net periodic benefit cost were $3.4 million. For the nine months ended September 30, 2021, regulatory deferrals related to net periodic benefit cost were not material.

We use a December 31 measurement date for our plans. On April 30, 2022, we amended our defined benefit pension plans to change the variable cost of living adjustment for eligible participants to a fixed rate. Accordingly, we remeasured our net benefit obligations as of April 30, 2022, resulting in an adjustment of approximately $7.2 million to our pension expense, net of capitalization and regulatory deferrals, for the year ending December 31, 2022, beginning May 1, 2022.

We capitalize all eligible service cost and non-service cost components under the accounting requirements of ASC Topic 980 (Regulated Operations) for rate-regulated entities. Our consolidated balance sheets reflect the capitalized non-service cost components as a regulatory asset in the amount of $4.0 million and $6.1 million at September 30, 2022 and December 31, 2021, respectively. See Note 3 of the Notes to Consolidated Financial Statements in this Quarterly Report for additional information.