Condensed consolidated statements of cash flows (Parenthetical) - USD ($) $ in Millions	6 Months Ended
Jun. 30, 2019	Jun. 30, 2018
Statement of cash flows [abstract]
Cash acquired from acquisition	$ 3	$ 11
Cash disposed	$ 34	$ 0

The amount of cash and cash equivalents in subsidiaries or other businesses over which control is obtained or lost. [Refer: Subsidiaries [member]; Cash and cash equivalents]

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 7
-IssueDate 2018-01-01
-Paragraph 40
-Subparagraph c
-URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=7&date=2018-03-01&anchor=para_40_c&doctype=Standard
-URIDate 2018-03-16

Name:	ifrs-full_CashAndCashEquivalentsInSubsidiaryOrBusinessesAcquiredOrDisposed2013
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration