EMPLOYEE BENEFIT PLANS (Tables)

9 Months Ended

Jun. 30, 2015

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)	2015			2014			2015			2014			2015			2014			2015			2014
Service cost	$	1,872		$	1,536		$	5,614		$	4,608		$	1,063		$	980		$	3,190		$	2,942
Interest cost	2,549			2,517			7,649			7,550			1,434			1,434			4,304			4,300
Expected return on plan assets	(4,272		)	(3,869		)	(12,817		)	(11,607		)	(1,245		)	(1,043		)	(3,733		)	(3,130		)
Recognized actuarial loss	1,747			1,399			5,239			4,197			737			625			2,208			1,875
Prior service cost amortization	28			27			83			83			(91		)	(89		)	(273		)	(267		)
Recognized net initial obligation	—			—			—			—			—			3			—			8
Net periodic benefit cost	$	1,924		$	1,610		$	5,768		$	4,831		$	1,898		$	1,910		$	5,696		$	5,728