Property, plant and equipment - Capital commitments (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Property, plant and equipment
Contracted for	$ 101	$ 116	$ 33
Not contracted for	14	20	7
Total	$ 115	$ 136	$ 40

The amount of capital commitments that have been authorised by the entity, but for which the entity has not entered into a contract. [Refer: Capital commitments]

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Name IAS
-Number 1
-IssueDate 2017-01-01
-Paragraph 112
-Subparagraph c
-URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=1&date=2017-03-01&anchor=para_112_c&doctype=Standard
-URIDate 2017-03-09

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- Definition

The amount of future capital expenditures that the entity is committed to make.

+ References

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- Definition

The amount of capital commitments for which the entity has entered into a contract. [Refer: Capital commitments]

+ References

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- References

No definition available.

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