Stock-Based Compensation Plans - Summary of Assumptions Used to Determine Fair Value of Options Granted (Detail) - NSRs [Member]	12 Months Ended
Dec. 31, 2018 yr
Disclosure of terms and conditions of share-based payment arrangement [Line Items]
Risk-Free Interest Rate	1.90%
Expected Dividend Yield	1.66%
Expected Volatility	28.47%
Expected Life	4.50

The expected volatility of the share price used to calculate the fair value of the share options granted. Expected volatility is a measure of the amount by which a price is expected to fluctuate during a period. The measure of volatility used in option pricing models is the annualised standard deviation of the continuously compounded rates of return on the share over a period of time.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 2
-IssueDate 2017-01-01
-Paragraph 47
-Subparagraph a
-Clause i
-URI http://eifrs.ifrs.org/eifrs/XBRL?type=IFRS&num=2&date=2017-03-01&anchor=para_47_a_i&doctype=Standard
-URIDate 2017-03-09

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- Definition

The option life of share options granted.

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- Definition

The implied yield currently available on zero-coupon government issues of the country in whose currency the exercise price for share options granted is expressed, with a remaining term equal to the expected term of the option being valued (based on the option's remaining contractual life and taking into account the effects of expected early exercise). [Refer: Government [member]]

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- Definition

Line items represent concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes of the table.

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- Definition

The percentage of an expected dividend used to calculate the fair value of share options granted.

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