EMPLOYEE BENEFIT PLANS - DEFINED BENEFIT PLANS (Details) (USD $)	3 Months Ended
	Dec. 31, 2014	Dec. 31, 2013
Components of net periodic cost
Defined benefit plan, contributions by employer	$ 0
Pension [Member]
Components of net periodic cost
Service cost	1,871,000	1,536,000
Interest cost	2,550,000	2,516,000
Expected return on plan assets	(4,272,000)	(3,869,000)
Recognized actuarial loss	1,745,000	1,399,000
Prior service cost amortization	28,000	28,000
Recognized net initial obligation	0	0
Net periodic cost	1,922,000	1,610,000
OPEB [Member]
Components of net periodic cost
Service cost	1,063,000	981,000
Interest cost	1,435,000	1,433,000
Expected return on plan assets	(1,244,000)	(1,044,000)
Recognized actuarial loss	736,000	625,000
Prior service cost amortization	(91,000)	(89,000)
Recognized net initial obligation	0	3,000
Net periodic cost	$ 1,899,000	$ 1,909,000