PENSION AND OTHER POST-EMPLOYMENT BENEFITS - Assumptions Used to Determine Net Periodic Benefit Cost (Details)	2 Months Ended	10 Months Ended	12 Months Ended
	Feb. 26, 2020	Dec. 31, 2020	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Pension
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Expected long-term return on plan assets			7.50%	7.50%	7.50%
Rate of compensation increase			4.10%	4.10%	4.20%
Pension | Service Cost
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Weighted-average discount rate	3.60%	3.24%		4.66%	3.75%
Pension | Interest Cost
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Weighted-average discount rate	3.27%	2.90%		4.37%	3.75%
OPEB
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Expected long-term return on plan assets			7.50%	7.50%	7.50%
OPEB | Service Cost
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Weighted-average discount rate	3.63%	3.29%		4.67%	3.50%
OPEB | Interest Cost
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Weighted-average discount rate	2.71%	2.30%		3.89%	3.50%