RESTRUCTURING CHARGES (Narrative) (Details)	1 Months Ended	3 Months Ended	12 Months Ended
	Jun. 30, 2019 T Employee	Mar. 31, 2017 USD ($)	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)	Jul. 19, 2017 T	Dec. 31, 2016 USD ($)
Restructuring Cost and Reserve [Line Items]
Decrease in production capacity | T						200,000
Accelerated depreciation		$ 6,000,000
Closure of Luke Mill
Restructuring Cost and Reserve [Line Items]
Restructuring charges			$ 4,000,000	$ 0
Annual production capacity | T	2,700,000
Number of positions eliminated | Employee	675
Accelerated depreciation			76,000,000
Facility Closing
Restructuring Cost and Reserve [Line Items]
Restructuring charges			0	0	$ 2,000,000		$ 3,000,000
Androscoggin - Wickliffe Capacity Reduction
Restructuring Cost and Reserve [Line Items]
Restructuring charges			$ 0	$ 0	$ 1,000,000		$ 6,000,000
Accelerated depreciation		$ 6,000,000
Coated Freesheet | Closure of Luke Mill
Restructuring Cost and Reserve [Line Items]
Decrease in production capacity | T	450,000