DEBT - SCHEDULE OF LONG TERM DEBT (Details) (NJNG [Member], USD $)	3 Months Ended		12 Months Ended
	Dec. 31, 2012		Sep. 30, 2012
Debt Instrument [Line Items]
Sale leaseback transaction, gross proceeds	$ 7,100,000		$ 6,500,000
Bank Credit Facilities Short term [Member]
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity	$ 250,000,000	[1]	$ 200,000,000	[1]

[1] Committed credit facilities, which require commitment fees on the unused amounts.