DERIVATIVE INSTRUMENTS AND HEDGING ACTIVITIES - Gains or Losses Related to Changes in Fair Value and Cash Settlements on Derivatives Not Qualifying as Hedging Instruments (Details) - Not Designated as Hedging Instrument - Commodity contracts - USD ($) $ in Millions	2 Months Ended	3 Months Ended	7 Months Ended
	Feb. 28, 2017	Sep. 30, 2017	Sep. 30, 2017
Derivative Instruments, Gain (Loss) [Line Items]
Cash settlements		$ 1.2	$ 2.6
Change in fair value		(7.9)	(1.2)
Total gains (losses) on non-qualifying hedges		$ (6.7)	$ 1.4
Predecessor
Derivative Instruments, Gain (Loss) [Line Items]
Cash settlements	$ 0.0
Change in fair value	(1.8)
Total gains (losses) on non-qualifying hedges	$ (1.8)