COMMON STOCK EQUITY - NARRATIVE (Details) - USD ($) shares in Thousands, $ in Millions	3 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Equity [Abstract]
Equity raised through the DRP	$ 3.8	$ 4.6
Number of treasury shares issued from raising of equity through the DRP	90	139
Equity raised through the DRP waiver discount feature	$ 22.7
Shares issued through the DRP waiver discount feature (in shares)	554