DERIVATIVE FINANCIAL INSTRUMENTS AND HEDGING ACTIVITIES (Narrative) (Details) $ in Millions	9 Months Ended
	Sep. 30, 2020 USD ($)
Interest rate swap locks
Derivative [Line Items]
Amount de-designated and partially cash settled	$ 11.1
Derivatives designated as cash flow hedges | Derivatives designated as cash flow hedges | Treasury locks
Derivative [Line Items]
Gain (loss) on treasury lock recorded to AOCI	(20.8)
Derivatives designated as cash flow hedges | Derivatives designated as cash flow hedges | Interest rate swap locks
Derivative [Line Items]
Gain (loss) on treasury lock recorded to AOCI	(1.4)
Derivatives designated as cash flow hedges | Derivatives designated as cash flow hedges | Carbon option contracts
Derivative [Line Items]
AOCI gain (loss) balance expected to be reclassified in next twelve months, net of tax	$ 1.1
New Zealand JV | Forecasted Sales and Purchases, term 1
Derivative [Line Items]
Length of time, foreign currency cash flow hedge	12 months
New Zealand JV | Minimum | Forecasted Sales and Purchases, term 1
Derivative [Line Items]
Percent of forecast sales and purchases hedged for 12 months	50.00%
New Zealand JV | Minimum | Forecasted Sales and Purchases, term 2
Derivative [Line Items]
Length of time, foreign currency cash flow hedge	12 months
New Zealand JV | Minimum | Foreign Sales and Purchases, term 3
Derivative [Line Items]
Length of time, foreign currency cash flow hedge	18 months
New Zealand JV | Maximum | Forecasted Sales and Purchases, term 1
Derivative [Line Items]
Percent of forecast sales and purchases hedged for 12 months	90.00%
New Zealand JV | Maximum | Forecasted Sales and Purchases, term 2
Derivative [Line Items]
Length of time, foreign currency cash flow hedge	18 months
Percent of forecast sales and purchases hedged for 12 to 18 months	75.00%
New Zealand JV | Maximum | Foreign Sales and Purchases, term 3
Derivative [Line Items]
Length of time, foreign currency cash flow hedge	48 months
Percent of forecast sales and purchases hedged for 18 to 48 months	50.00%