Inventories (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2018	Dec. 31, 2017
Inventories [Abstract]
Cost of inventories recognized as expense	$ 2,758	$ 2,219

The amount of inventories recognised as an expense during the period. [Refer: Inventories]

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 2
-IssueDate 2017-01-01
-Paragraph 36
-Subparagraph d
-URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=2&date=2017-03-01&anchor=para_36_d&doctype=Standard
-URIDate 2017-03-09

Name:	ifrs-full_CostOfInventoriesRecognisedAsExpenseDuringPeriod
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration