Risk Management - Additional Information (Detail) $ in Millions	6 Months Ended
Jun. 30, 2018 USD ($) Contract
Disclosure of Nature and Extent of Risks Arising from Financial Instruments [Line Items]
Number of foreign exchange contracts outstanding \| Contract	0
Interest rate swap contract [Member]
Disclosure of Nature and Extent of Risks Arising from Financial Instruments [Line Items]
Total Debt Principal \| $	$ 400

The nominal or face amount of a financial instrument, used to calculate payments made on that instrument.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Name IAS
-Number 1
-IssueDate 2017-01-01
-Paragraph 112
-Subparagraph c
-URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=1&date=2017-03-01&anchor=para_112_c&doctype=Standard
-URIDate 2017-03-09

Name:	ifrs-full_NotionalAmount
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	na
Period Type:	instant