SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES PPE Utility (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Property, Plant and Equipment [Line Items]
Public Utilities, Property, Plant and Equipment, Plant in Service	$ 2,652,244	$ 2,424,134
Accumulated depreciation for nonutility property and equipment	(194,913)	(151,084)
Accumulated Depreciation	(498,161)	(471,222)
Nonutility Property and Equipment, at cost	741,027	821,942
Solar Assets
Property, Plant and Equipment [Line Items]
Nonutility Property and Equipment, at cost	582,379	652,683
Cogeneration Assets
Property, Plant and Equipment [Line Items]
Nonutility Property and Equipment, at cost	125,614	124,172
Property, Plant and Equipment, Other Types
Property, Plant and Equipment [Line Items]
Nonutility Property and Equipment, at cost	33,034	45,087
South Jersey Gas Company
Property, Plant and Equipment [Line Items]
Production Plant	296	296
Storage Plant	61,909	60,661
Transmission Plant	258,598	257,169
Distribution Plant	2,044,421	1,871,703
General Plant	175,599	169,464
Other Plant	1,855	1,855
Utility Plant In Service	2,542,678	2,361,148
Construction Work In Progress	109,566	62,986
Public Utilities, Property, Plant and Equipment, Plant in Service	2,652,244	2,424,134
Accumulated Depreciation	$ (498,161)	$ (471,222)