- DEBT (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Sep. 30, 2017
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Capital leases	$ 41,800	$ 39,700
Level 2 | Carrying Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, fair value	1,097,045	1,097,045
Level 2 | Fair market value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, fair value	1,084,268	1,107,676
Natural Gas Distribution
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt Issuance Costs, Gross	6,100	6,300
NJR
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt Issuance Costs, Gross	$ 768	$ 770