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Average number of employees - Summary of average number of employees (Parenthetical) (Detail) - Employee | 12 Months Ended
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Dec. 31, 2018 | Dec. 31, 2017 | Dec. 31, 2016
Disclosure of average number of employees [Line Items] |  |  |
Average number of employees | 47,458 | 46,807 | 51,029
Singapore [member] |  |  |
Disclosure of average number of employees [Line Items] |  |  |
Average number of employees | 422 | 434 | 262
India [member] |  |  |
Disclosure of average number of employees [Line Items] |  |  |
Average number of employees | 288 | 310 | 280

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- Definition The average number of personnel employed by the entity during a period. + References 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 + Details
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- Definition Disclosure of average number of employees.. + References No definition available. + Details
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- Details
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- Details
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