Statements of Consolidated Comprehensive Income (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011		Dec. 31, 2010		Dec. 31, 2009
Net Income	$ 89,291		$ 66,652		$ 57,874
Other Comprehensive Income (Loss), Net of Tax:
Postretirement Liability Adjustment	(5,667)	[1]	(3,302)	[1]	1,208	[1]
Unrealized (Loss) Gain on Available-for-Sale Securities	(360)	[1]	339	[1]	533	[1]
Unrealized (Loss) Gain on Derivatives - Other	(788)	[1]	249	[1]	958	[1]
Other Comprehensive Income of Affiliated Companies	189	[1]	371	[1]	2,031	[1]
Other Comprehensive Loss- Net of Tax	(6,626)	[1]	(2,343)	[1]	4,730	[1]
Comprehensive Income	82,665		64,309		62,604
Less: Comprehensive Loss Attributable to Noncontrolling Interest in Subsidiaries	0		0		231
Comprehensive Income Attributable to South Jersey Industries, Inc. Shareholders	$ 82,665		$ 64,309		$ 62,835
Combined statutory tax rate	41.00%		41.00%		41.00%

[1] Determined using a combined statutory tax rate of 41%.