EMPLOYEE BENEFIT PLANS (Tables)

6 Months Ended

Jun. 30, 2022

Employee Benefit Plans [Line Items]

Schedule of Net Benefit Costs [Table Text Block]

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				Six Months Ended
	June 30,				June 30,
	2022		2021		2022		2021
	(Thousands of dollars)
Components of net periodic benefit cost
Service cost	$	2,592	$	3,453	$	5,686	$	6,906
Interest cost	9,037		7,365		16,841		14,730
Expected return on assets	(14,632)		(15,596)		(29,245)		(31,192)
Amortization of unrecognized prior service cost	62		—		62		—
Amortization of net loss	4,198		11,381		12,345		22,762
Net periodic benefit cost	$	1,257	$	6,603	$	5,689	$	13,206

	Other Postemployment Benefits
	Three Months Ended				Six Months Ended
	June 30,				June 30,
	2022		2021		2022		2021
	(Thousands of dollars)
Components of net periodic benefit cost (credit)
Service cost	$	318	$	397	$	636	$	794
Interest cost	1,612		1,563		3,224		3,126
Expected return on assets	(3,295)		(4,202)		(6,590)		(8,404)
Amortization of unrecognized prior service cost (credit)	10		(70)		20		(140)
Amortization of net loss	54		93		108		186
Net periodic benefit cost (credit)	$	(1,301)	$	(2,219)	$	(2,602)	$	(4,438)