RELINQUISHMENT AGREEMENT (Details) (USD $)	0 Months Ended	3 Months Ended		6 Months Ended
	Jan. 01, 2000	Mar. 31, 2015	Mar. 31, 2014	Mar. 31, 2015	Mar. 31, 2014	Sep. 30, 2014	Sep. 30, 1998
RELINQUISHMENT AGREEMENT [Abstract]
Term of relinquishment agreement	15 years
Relinquishment liability		$ 0		$ 0		$ 25,200,000	$ 549,100,000
Relinquishment liability reassessment		299,000	0	243,000	0
Accretion of discount to the relinquishment liability		0	551,000	227,000	1,102,000
Relinquishment Payments [Abstract]
Principal				24,400,000	23,457,000
Accretion of discount				778,000	1,794,000
Total relinquishment payments				25,200,000	25,300,000
Accrued relinquishment payments		$ 0		$ 0		$ 13,200,000