XML 12 R39.htm IDEA: XBRL DOCUMENT v2.4.1.9
FINANCIAL INSTRUMENTS 2 (Details) (Derivatives Energy Related Assets, Supplier Concentration Risk, USD $)
In Millions, unless otherwise specified
3 Months Ended
Mar. 31, 2015
Derivatives Energy Related Assets | Supplier Concentration Risk
 
Concentration Risk [Line Items]  
Amount of derivatives - energy related assets with single retail counterparty $ 11.6us-gaap_FairValueConcentrationOfRiskDerivativeFinancialInstrumentsAssets
/ us-gaap_ConcentrationRiskByBenchmarkAxis
= sji_DerivativesEnergyRelatedAssetsMember
/ us-gaap_ConcentrationRiskByTypeAxis
= us-gaap_SupplierConcentrationRiskMember
Percentage of derivatives - energy related assets with a single retail counterparty (in hundredths) 17.30%us-gaap_ConcentrationRiskPercentage1
/ us-gaap_ConcentrationRiskByBenchmarkAxis
= sji_DerivativesEnergyRelatedAssetsMember
/ us-gaap_ConcentrationRiskByTypeAxis
= us-gaap_SupplierConcentrationRiskMember