EARNINGS PER SHARE (Details) - USD ($) $ / shares in Units, $ in Thousands		3 Months Ended		9 Months Ended
		Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Earnings Per Share [Abstract]
Net (loss) income, as reported		$ (17,363)	$ (7,460)	$ 106,272	$ 176,763
Basic earnings per share
Weighted average shares of common stock outstanding-basic (shares)		85,960,000	85,449,000	85,823,000	85,110,000
Basic earnings per common share (usd per share)		$ (0.20)	$ (0.09)	$ 1.24	$ 2.08
Diluted earnings per share
Weighted average shares of common stock outstanding-basic (shares)		85,960,000	85,449,000	85,823,000	85,110,000
Incremental shares	[1]	0	0	868,000	1,018,000
Weighted average shares of common stock outstanding-diluted (shares)		85,960,000	85,449,000	86,691,000	86,128,000
Diluted (loss) earnings per common share (usd per share)	[2]	$ (0.20)	$ (0.09)	$ 1.23	$ 2.05
Incremental shares not included in the computation of diluted loss per common share		897,000	1,018,000
Anti-dilutive shares excluded from the calculation of diluted earnings per share				0	0

[1] Incremental shares consist primarily of unvested stock awards and performance shares.

[2] Since there was a net loss for the three months ended June 30, 2016, and 2015, incremental shares of 897 and 1,018, respectively, were not included in the computation of diluted loss per common share, as their effect would have been anti-dilutive.There were no anti-dilutive shares excluded from the calculation of diluted earnings per share for the nine months ended June 30, 2016 and 2015.