COMMITMENTS AND CONTINGENCIES Environmental Remediation Obligations (Details) - USD ($)	3 Months Ended	6 Months Ended		9 Months Ended	12 Months Ended
	Mar. 31, 2020	Jun. 30, 2018	Jun. 30, 2016	Sep. 30, 2016	Dec. 31, 2017	Mar. 31, 2022	Dec. 31, 2019
Loss Contingencies [Line Items]
Accrual for environmental loss contingencies						$ 182,000,000
Accrual for environmental loss contingencies, gross						190,000,000
Liability for Asbestos and Environmental Claims, Net						101,000,000
Cass Lake, Minnesota
Loss Contingencies [Line Items]
Accrual for environmental loss contingencies						$ 46,000,000
Kalamazoo River Superfund Site
Loss Contingencies [Line Items]
Proposed consent decree, value of remediation payments							$ 100,000,000
Proposed consent decree, value of labor performed							$ 136,000,000
Kalamazoo River Superfund Site | Time Critical Removal Action
Loss Contingencies [Line Items]
Loss contingency, damages sought, value			$ 19,000,000	$ 37,000,000
Kalamazoo River Superfund Site | Georgia-Pacific Consumer Products LP, Fort James Corporation and Georgia Pacific LLC Cost Recovery Action
Loss Contingencies [Line Items]
Loss contingency, damages sought, value		$ 79,000,000
Responsible party percentage		15.00%
Loss Contingency, damages awarded, value		$ 50,000,000
San Jacinto River Superfund Site
Loss Contingencies [Line Items]
Loss contingency, damages sought, value					$ 115,000,000
Responsible party percentage	50.00%
San Jacinto River Superfund Site | Northern impoundment [Member]
Loss Contingencies [Line Items]
Loss contingency, damages sought, value					105,000,000
Liability for Asbestos and Environmental Claims, Net	$ 55,000,000
San Jacinto River Superfund Site | Southern Impoundment [Member]
Loss Contingencies [Line Items]
Loss contingency, damages sought, value					$ 10,000,000
Liability for Asbestos and Environmental Claims, Net	$ 10,000,000