RELINQUISHMENT AGREEMENT (Details) (USD $)	3 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Sep. 30, 2014	Sep. 30, 1998
RELINQUISHMENT AGREEMENT [Abstract]
Term of relinquishment agreement	15 years
Period following the end of the first three-month period after the relinquishment date upon which senior relinquishment payments start	25 days
Period following the end of the first six-month period after the relinquishment date upon which junior relinquishment payments start	25 days
Relinquishment payment rate as a percent of revenues	2.50%
Relinquishment liability	$ 18,900,000		$ 25,200,000	$ 549,100,000
Accretion of discount to the relinquishment liability	227,000	551,000
Relinquishment liability reassessment	56,000	0
Accrued relinquishment payments	18,900,000		13,200,000
Relinquishment Payments [Abstract]
Principal	6,336,000	6,034,000
Accretion of discount	276,000	621,000
Total	$ 6,600,000	$ 6,600,000