COMMITMENTS AND CONTINGENCIES (Details) $ in Millions	3 Months Ended	9 Months Ended
	Dec. 31, 2017 USD ($)	Sep. 30, 2017
Commitments and Contingencies [Line Items]
Number Of Former Manufactured Gas Sites Where We Own Or Retain Legal Responsibility For Environmental Conditions		12
Number of sites where we have completed or addressed removal of the source of soil contamination according to plans approved by KDHE.		11
Number of sites with ongoing groundwater monitoring		8
Number of sites where regulatory closure has been achieved		3
Environmental Reserve Estimate Range, Low		4
Environmental Reserve Estimate Range, High		7
Environmental Reserve Estimate, Actual		4
Percentage yield of high consequence pipeline areas		30.00%
Subsequent Event [Member]
Commitments and Contingencies [Line Items]
AAO associated with MGP costs requested amount, cap	$ 15.0
Regulatory asset expected to be recorded for MGP costs accrued at January 1, 2017	$ 5.9