Provisions - Additional Information (Detail) $ in Millions	12 Months Ended
Dec. 31, 2016 USD ($)
Disclosure Of Litigation Settlement [Abstract]
Litigation expenses	$ 12
Insurance recovery of litigation expenses	$ 8

The amount used (ie incurrent and charged against the provision) for other provisions. [Refer: Other provisions]

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 37
-IssueDate 2017-01-01
-Paragraph 84
-Subparagraph c
-URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=37&date=2017-03-01&anchor=para_84_c&doctype=Standard
-URIDate 2017-03-09

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