EMPLOYEE BENEFIT PLANS (Tables)

9 Months Ended

Jun. 30, 2016

Compensation and Retirement Disclosure [Abstract]

Schedule of Net Benefit Costs

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)	2016			2015			2016			2015			2016			2015			2016			2015
Service cost	$	1,897		$	1,872		$	5,693		$	5,614		$	1,130		$	1,063		$	3,391		$	3,190
Interest cost	2,836			2,549			8,507			7,649			1,564			1,434			4,692			4,304
Expected return on plan assets	(5,029		)	(4,272		)	(15,088		)	(12,817		)	(1,211		)	(1,245		)	(3,633		)	(3,733		)
Recognized actuarial loss	1,820			1,747			5,461			5,239			819			737			2,456			2,208
Prior service cost amortization	28			28			83			83			(91		)	(91		)	(273		)	(273		)
Net periodic benefit cost	$	1,552		$	1,924		$	4,656		$	5,768		$	2,211		$	1,898		$	6,633		$	5,696