Investments Securities - Summary of Investments in Short-Term Debt Securities (Detail) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Disclosure of detailed information about borrowings [abstract]
Investment in unquoted companies	$ 84	$ 76
Investment on debt securities	24	24
Non-current investments,Total	108	100
Investment on debt securities	87	1,304
Current investments,Total	$ 87	$ 1,304

The amount of current financial assets at fair value through other comprehensive income. [Refer: Financial assets at fair value through other comprehensive income]

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 7
-IssueDate 2018-01-01
-Paragraph 8
-Subparagraph h
-URI http://eifrs.ifrs.org/eifrs/XBRL?type=IFRS&num=7&date=2018-03-01&anchor=para_8_h&doctype=Standard
-URIDate 2018-03-16

Name:	ifrs-full_CurrentFinancialAssetsAtFairValueThroughOtherComprehensiveIncome
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant