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FINANCIAL RISK MANAGEMENT - Translation exposure (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Canada, Dollars
FINANCIAL RISK MANAGEMENT
Impact of 10% change in foreign exchange rates	$ 21.3	$ 21.0
Mexico, Pesos
FINANCIAL RISK MANAGEMENT
Impact of 10% change in foreign exchange rates	$ 0.9	$ 1.8

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- Definition

Line items represent concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes of the table.

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- Definition

It represents the net impact from increase decrease in domestic currency rate.

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