SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details) $ in Thousands, number in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2018 USD ($)	Sep. 30, 2017 USD ($)	Sep. 30, 2018 USD ($)	Sep. 30, 2017 USD ($)
Significant Accounting Policies [Line Items]
Other Nonoperating Income (Expense)	$ (1,929)	$ (3,715)	$ (6,287)	$ (11,022)
Number of natural gas distribution services customers	2		2
Segment Reporting, Disclosure of Major Customers	0	0	0	0
Capital Expenditures Incurred but Not yet Paid			$ 11,500	$ 2,200