EMPLOYEE BENEFIT PLANS (Tables)

9 Months Ended

Jun. 30, 2024

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)	2024		2023		2024		2023		2024		2023		2024		2023
Service cost	$	1,244	$	1,350	$	3,732	$	4,051	$	254	$	618	$	1,151	$	1,854
Interest cost	4,060		3,794		12,180		11,381		1,809		2,286		6,519		6,859
Expected return on plan assets	(5,087)		(4,993)		(15,260)		(14,979)		(2,021)		(1,680)		(5,899)		(5,041)
Recognized actuarial loss	29		75		88		225		1,256		—		3,007		—
Prior service cost (credit) amortization	16		25		47		76		(3,339)		—		(6,676)		—
Net periodic benefit cost (credit)	$	262	$	251	$	787	$	754	$	(2,041)	$	1,224	$	(1,898)	$	3,672