ASSET RETIREMENT OBLIGATIONS (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2015	Sep. 30, 2014
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Balance at period beginning	$ 30,495	$ 28,711
Accretion	2,262	2,012
Additions	2,185	925
Revisions in estimated cash flows	(14,763)	0
Retirements	(1,034)	(1,153)
Balance at period end	19,145	$ 30,495
Estimated Accretion
2016	1,211
2017	1,273
2018	1,340
2019	1,403
2020	1,469
Total	$ 6,696