NATURE OF THE BUSINESS (Details) - Jun. 30, 2015 customer in Thousands	subsidiary customer
Steckman Ridge [Member]
Nature of Business [Line Items]
Equity method investment, ownership percentage	50.00%
Iroquois [Member]
Nature of Business [Line Items]
Equity method investment, ownership percentage	5.53%
PennEast [Member]
Nature of Business [Line Items]
Equity method investment, ownership percentage	20.00%
NJNG [Member]
Nature of Business [Line Items]
Total retail customers | customer	512
NJR Retail Holdings Corporation [Member]
Nature of Business [Line Items]
Number of principal subsidiaries	2