DIVESTITURES Narrative (Details) R$ in Millions, $ in Millions	3 Months Ended			9 Months Ended
	Sep. 30, 2020 USD ($)	Jun. 30, 2020 USD ($)	Sep. 30, 2019 USD ($)	Sep. 30, 2020 USD ($)	Sep. 30, 2020 BRL (R$)	Sep. 30, 2019 USD ($)
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Net (gains) losses on sales and impairments of businesses	$ (5.0)		$ 8.0	$ 347.0		$ 153.0
APPM [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Cost-method Investments, Realized Gain (Loss), Excluding Other than Temporary Impairments		$ 6.0
Disposal Group, Held-for-sale, Not Discontinued Operations [Member] | Brazilian Industrial Packaging
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Estimated proceeds from divestiture of business				$ 58.5	R$ 330
Proceeds to be received at closing | R$					280
Deferred proceeds on disposal of business | R$					R$ 50
Number of containerboard mill to be sold				3	3
Number of box plants to be sold				4	4
Net (gains) losses on sales and impairments of businesses				$ 347.0
Net (gains) losses on sales and impairments of businesses, net of tax				$ 340.0