PENSION AND OTHER POSTRETIREMENT PLANS - Amounts of AOCI Expected to be Recognized in Net Periodic Benefit Costs (Details) $ in Thousands	12 Months Ended
	Sep. 30, 2016 USD ($)
Pension
Defined Benefit Plan Disclosure [Line Items]
Net actuarial loss	$ 10,035
Prior service cost	(181)
Other Postretirement
Defined Benefit Plan Disclosure [Line Items]
Net actuarial loss	0
Prior service cost	$ (195)