SUMMARY OF BUSINESS AND BASIS OF PRESENTATION - Revenue (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Revenue from External Customer [Line Items]
Net sales	$ 2,444	$ 2,682
End-users and Converters
Revenue from External Customer [Line Items]
Net sales	1,119	1,091
Brokers and Merchants
Revenue from External Customer [Line Items]
Net sales	936	1,172
Printers
Revenue from External Customer [Line Items]
Net sales	389	419
Paper
Revenue from External Customer [Line Items]
Net sales	2,224	2,476
Packaging
Revenue from External Customer [Line Items]
Net sales	103	67
Pulp
Revenue from External Customer [Line Items]
Net sales	$ 117	$ 139