INCOME AND MINING TAXES (Details 3) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2017	Dec. 31, 2016
Income and mining taxes [Abstract]
Balance at the beginning of the year	$ (230.3)	$ (275.5)
Recognized in net loss	139.2	20.0
Recognized in other comprehensive income	1.8	20.4
Recognized as reduction in mineral properties	(43.6)	(6.9)
Recognized as foreign exchange	50.3	12.0
Other	2.0	(0.3)
Reclassified as held-for-sale	(18.2)	0.0
Total movement in the net deferred tax liabilities	$ (78.7)	$ (230.3)

The amount of tax expense or income relating to changes in deferred tax liabilities and deferred tax assets, recognised in profit or loss. [Refer: Deferred tax assets; Deferred tax expense (income); Deferred tax liabilities]

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
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- Definition

The amount of deferred tax liabilities or assets. [Refer: Deferred tax liabilities; Deferred tax assets]

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
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The amount of income tax relating to amounts recognised in other comprehensive income. [Refer: Other comprehensive income]

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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The increase (decrease) in deferred tax liability (asset) resulting from the net exchange differences arising when the financial statements are translated from the functional currency into a different presentation currency, including the translation of a foreign operation into the presentation currency of the reporting entity. [Refer: Deferred tax liability (asset)]

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
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- Definition

The amounts reclassified as held for sale.

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The increase (decrease) in deferred tax liability (asset) resulting from other.

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The decrease in deferred tax liability (asset) resulting from the reduction in mineral properties

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