ASSET RETIREMENT OBLIGATIONS (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2016	Sep. 30, 2015
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Balance at period beginning	$ 19,145	$ 30,495
Accretion	1,206	2,262
Additions	3,111	2,185
Revisions in estimated cash flows	5,320	(14,763)
Retirements	(403)	(1,034)
Balance at period end	28,379	$ 19,145
Estimated Accretion
2017	1,552
2018	1,639
2019	1,712
2020	1,789
2021	1,870
Total	$ 8,562