Per Share Information - Schedule of Per Share Information (Detail) - shares shares in Millions	12 Months Ended
Dec. 31, 2018	Dec. 31, 2017
Earnings per share [abstract]
Basic weighted average number of shares outstanding	869	862
Effect of dilutive stock options and restricted share units		3
Diluted weighted average number of shares outstanding	869	865

Dilutive effect of share options and restricted stock units on number of ordinary shares.

No definition available.

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- Definition

The weighted average number of ordinary shares outstanding plus the weighted average number of ordinary shares that would be issued on the conversion of all the dilutive potential ordinary shares into ordinary shares. [Refer: Ordinary shares [member]; Weighted average [member]]

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 33
-IssueDate 2018-01-01
-Paragraph 70
-Subparagraph b
-URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=33&date=2018-03-01&anchor=para_70_b&doctype=Standard
-URIDate 2018-03-16

+ Details

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- References

No definition available.

+ Details

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- Definition

The number of ordinary shares outstanding at the beginning of the period, adjusted by the number of ordinary shares bought back or issued during the period multiplied by a time-weighting factor.

+ References

+ Details

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