v3.10.0.1
FAIR VALUE OF FINANCIAL INSTRUMENTS - Non-Recurring basis (Details) - USD ($)
$ in Millions
3 Months Ended 12 Months Ended
Sep. 30, 2018
Dec. 31, 2018
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Goodwill, Impairment Loss $ 0.7  
Impairment - Market Assets   $ 2.1
Impairment - Assets Held for Sale   26.9
Impairment - Bonneville Assets held for Sale   25.6
Impairment - Other assets held for sale   $ 1.3