Risk Management Policy - Schedule of Financial Debt Structure Detailed by Interest Rates Net of Hedging Derivative Instruments (Detail)	Dec. 31, 2017	Dec. 31, 2016
Fixed Interest Rate [Member] \| Interest Rate Risk [Member]
Disclosure Of Risk Management Strategy Related To Hedge Accounting [Line Items]
Fixed interest rate	92.00%	92.00%

The interest rate on borrowings. [Refer: Borrowings]

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Name IFRS
-Number 7
-IssueDate 2016-01-13
-Paragraph 7
-URI http://eifrs.ifrs.org/eifrs/XBRL?type=IFRS&num=7&date=2016-03-30&anchor=para_7&doctype=Standard
-URIDate 2016-03-31

Name:	ifrs-full_BorrowingsInterestRate
Namespace Prefix:	ifrs-full_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant