Assets Held For Sale and Discontinued Operations - Additional Information (Detail) € in Millions, $ in Billions		1 Months Ended
Jan. 02, 2018 USD ($)	Aug. 31, 2017	Dec. 31, 2017 EUR (€)
Disclosure Of Assets Held For Sale And Discontinued Operations [Abstract]
Disposal percentage		100.00%
Total consideration received \| $	$ 2.6
Total gains recognised in other comprehensive income and accumulated in equity relating to assets held for sale \| €			€ 32

The amount recognised in other comprehensive income and accumulated in equity, relating to non-current assets or disposal groups held for sale. [Refer: Non-current assets or disposal groups classified as held for sale; Other reserves; Other comprehensive income; Disposal groups classified as held for sale [member]]

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 5
-IssueDate 2016-01-13
-Paragraph 38
-URI http://eifrs.ifrs.org/eifrs/XBRL?type=IFRS&num=5&date=2016-03-30&anchor=para_38&doctype=Standard
-URIDate 2016-03-31

Reference 2: http://www.xbrl.org/2003/role/exampleRef
-Name IFRS
-Number 5
-IssueDate 2016-01-13
-Section Example 12
-URI http://eifrs.ifrs.org/eifrs/XBRL?type=IFRS&num=5&date=2016-03-30&anchor=sect_Example12&doctype=Implementation%20Guidance
-URIDate 2016-03-31

Name:	ifrs-full_AmountRecognisedInOtherComprehensiveIncomeAndAccumulatedInEquityRelatingToNoncurrentAssetsOrDisposalGroupsHeldForSale
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant