VALUATION AND QUALIFYING ACCOUNTS (Details) - USD ($) $ in Thousands		12 Months Ended
		Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2013
Allowance for Doubtful Accounts [Member]
Movement in Valuation Allowances and Reserves [Roll Forward]
BEGINNING BALANCE		$ 5,357	$ 5,330	$ 4,797
ADDITIONS CHARGED TO EXPENSE		2,859	2,504	2,627
OTHER	[1]	(3,027)	(2,477)	(2,094)
ENDING BALANCE		$ 5,189	5,357	5,330
Regulatory Asset [Member]
Movement in Valuation Allowances and Reserves [Roll Forward]
BEGINNING BALANCE			$ 0	71
ADDITIONS CHARGED TO EXPENSE				(71)
OTHER	[1]			0
ENDING BALANCE				$ 0

[1] Uncollectible accounts written off, less recoveries and adjustments.