DERIVATIVE INSTRUMENTS 3 (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012		Dec. 31, 2011		Dec. 31, 2010
Derivative Instruments, Gain (Loss) [Line Items]
Losses reclassified from accumulated OCI into income	$ (46)	[1]	$ (46)	[1]	$ (46)	[1]
South Jersey Resource Group [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Realized gains losses, derivative instruments on energy-related contracts	$ 15,407		$ 12,872		$ 23,526

[1] Included in Interest Charges