SUPPLEMENTAL CASH FLOW INFORMATION - Interest and Income Taxes Paid (Details) - USD ($) $ in Millions	6 Months Ended
Jun. 30, 2018	Jun. 30, 2017
Cash Flow Statement [Abstract]
Interest paid	$ 94	$ 41
Income taxes paid	$ 30	$ 20

The cash flows from income taxes paid or refunded.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 7
-IssueDate 2017-01-01
-Paragraph 35
-URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=7&date=2017-03-01&anchor=para_35&doctype=Standard
-URIDate 2017-03-09

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration