EMPLOYEE BENEFIT PLANS (Tables)

9 Months Ended

Jun. 30, 2022

Retirement Benefits [Abstract]

Components of Net Periodic Cost

The components of the net periodic cost for pension benefits, including the Company's Pension Equalization Plan, and OPEB costs (principally health care and life insurance) for employees and covered dependents were as follows:

	Pension								OPEB
	Three Months Ended				Nine Months Ended				Three Months Ended				Nine Months Ended
	June 30,				June 30,				June 30,				June 30,
(Thousands)	2022		2021		2022		2021		2022		2021		2022		2021
Service cost	$	2,073	$	2,182	$	6,219	$	6,547	$	1,077	$	1,211	$	3,229	$	3,633
Interest cost	2,408		2,278		7,224		6,834		1,588		1,518		4,766		4,553
Expected return on plan assets	(5,319)		(5,037)		(15,956)		(15,112)		(1,893)		(1,625)		(5,681)		(4,873)
Recognized actuarial loss	2,186		2,862		6,558		8,585		1,421		1,978		4,263		5,933
Prior service cost (credit) amortization	25		25		76		76		(35)		(44)		(107)		(134)
Net periodic benefit cost	$	1,373	$	2,310	$	4,121	$	6,930	$	2,158	$	3,038	$	6,470	$	9,112