LONG-TERM DEBT - Interest on Long-term Debt (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2018	Dec. 31, 2017
LONG-TERM DEBT
Interest expense	$ 87.4	$ 70.0
Borrowing costs capitalized	$ 7.9	$ 6.4
Capitalization rate (as a percent)	1.33%	1.37%

The amount of interest and other costs that an entity incurs in connection with the borrowing of funds that are directly attributable to the acquisition, construction or production of a qualifying asset and which form part of the cost of that asset.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 23
-IssueDate 2018-01-01
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-Subparagraph a
-URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=23&date=2018-03-01&anchor=para_26_a&doctype=Standard
-URIDate 2018-03-16

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- Definition

The weighted average of interest and other costs that an entity incurs in connection with the borrowing of funds applicable to the borrowings of the entity that are outstanding during the period, other than borrowings made specifically for the purpose of obtaining a qualifying asset. [Refer: Weighted average [member]; Borrowings]

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 23
-IssueDate 2018-01-01
-Paragraph 26
-Subparagraph b
-URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=23&date=2018-03-01&anchor=para_26_b&doctype=Standard
-URIDate 2018-03-16

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- References

No definition available.

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- Definition

The amount of interest expense on borrowings. [Refer: Interest expense; Borrowings]

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Name IAS
-Number 1
-IssueDate 2018-01-01
-Paragraph 112
-Subparagraph c
-URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=1&date=2018-03-01&anchor=para_112_c&doctype=Standard
-URIDate 2018-03-16

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