EARNINGS PER COMMON SHARE (Details) (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended								12 Months Ended
	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2012
Basic EPS:
Net income	$ (14.9)	$ 11.7	$ 52.2	$ 35.6	$ (9.6)	$ 6.6	$ 30.2	$ 25.6	$ 84.6	$ 52.8	$ 62.6
Less: Income allocated to participating securities									0.3	0.3	0.3
Net Income Available to Common Shareholders									84.3	52.5	62.3
Weighted Average Shares Outstanding, Basic (in Shares)									35.8	25.9	22.3
Basic Earnings Per Share of Common Stock (in dollars per share)	$ (0.35)	$ 0.34	$ 1.59	$ 1.09	$ (0.30)	$ 0.25	$ 1.34	$ 1.14	$ 2.36	$ 2.03	$ 2.80
Diluted EPS:
Net Income (Loss)	(14.9)	11.7	52.2	35.6	(9.6)	6.6	30.2	25.6	84.6	52.8	62.6
Less: Income allocated to participating securities									0.3	0.3	0.3
Net Income Available to Common Shareholders									$ 84.3	$ 52.5	$ 62.3
Weighted Average Shares Outstanding, Basic (in Shares)									35.8	25.9	22.3
Dilutive Effect of Stock Options, Restricted Stock, and Restricted Stock Units									0.1	0.1	0
Weighted Average Diluted Shares (in shares)									35.9	26.0	22.3
Diluted Earnings Per Share of Common Stock (in dollars per share)	$ (0.35)	$ 0.33	$ 1.59	$ 1.09	$ (0.30)	$ 0.25	$ 1.34	$ 1.14	$ 2.35	$ 2.02	$ 2.79
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Outstanding shares excluded from calculation of diluted EPS (in shares)									0.3	0.2	0.2
Stock Option Awards
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Outstanding shares excluded from calculation of diluted EPS (in shares)									0	0	0
Restricted stock and stock units subject to performance and/or market conditions
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Outstanding shares excluded from calculation of diluted EPS (in shares)									0.3	0.2	0.2