EARNINGS PER SHARE (Details) - USD ($) $ / shares in Units, $ in Thousands		3 Months Ended
		Dec. 31, 2015	Dec. 31, 2014
Earnings Per Share [Abstract]
Net income, as reported		$ 48,647	$ 123,320
Basic earnings per share
Weighted average shares of common stock outstanding-basic (shares)		85,675,000	84,552,000
Basic earnings per common share (usd per share)		$ 0.57	$ 1.46
Diluted earnings per share
Weighted average shares of common stock outstanding-basic (shares)		85,675,000	84,552,000
Incremental shares	[1]	1,001,000	1,022,000
Weighted average shares of common stock outstanding-diluted (shares)		86,676,000	85,574,000
Diluted earnings per common share (usd per share)	[2]	$ 0.56	$ 1.44
Anti-dilutive shares excluded from the calculation of diluted earnings per share		0	0

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

[2] There were no anti-dilutive shares excluded from the calculation of diluted earnings per share for the three months ended December 31, 2015, and 2014.