RATES AND REGULATORY ACTIONS (Details) - USD ($) $ in Millions		1 Months Ended
	Feb. 29, 2016	Jan. 31, 2016	Oct. 31, 2015
Energy Efficiency Tracker
Schedule of Capitalization [Line Items]
Decrease in amount of regulatory costs approved	$ 7.9
Basic Gas Supply Service
Schedule of Capitalization [Line Items]
Refunds to customers		$ 20.0
Approved rate decrease (as a percent)			10.30%
Accelerated Infrastructure Replacement Program
Schedule of Capitalization [Line Items]
Extension period of AIRP	7 years
Investment requested to be recovered through CIRT	$ 500.0
Investment requested to be recovered through end of 2016	$ 76.0