Acquisition of Businesses - Summary of Cash Flows Relating to Acquisitions (Detail) $ in Millions	12 Months Ended
Dec. 31, 2018 USD ($)
Disclosure of consideration transferred business combinations [line items]
Net cash outflow arising on acquisitions	$ 38
Regent [member]
Disclosure of consideration transferred business combinations [line items]
Cash paid on acquisition	13
UK Portfolio [member]
Disclosure of consideration transferred business combinations [line items]
Cash paid on acquisition	9
Contingent consideration paid	4
Settlement of stamp duty liability	14
Less: cash and cash equivalents acquired	(2)
Net cash outflow arising on acquisitions	$ 25

The amount of cash and cash equivalents in subsidiaries or other businesses over which control is obtained or lost. [Refer: Subsidiaries [member]; Cash and cash equivalents]

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 7
-IssueDate 2018-01-01
-Paragraph 40
-Subparagraph c
-URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=7&date=2018-03-01&anchor=para_40_c&doctype=Standard
-URIDate 2018-03-16

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- Definition

The aggregate cash flows used in obtaining control of subsidiaries or other businesses, classified as investing activities. [Refer: Subsidiaries [member]]

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 7
-IssueDate 2018-01-01
-Paragraph 39
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- Definition

The fair value, at acquisition date, of cash transferred as consideration in a business combination. [Refer: Business combinations [member]]

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 3
-IssueDate 2018-01-01
-Paragraph B64
-Subparagraph f
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Contingent consideration paid

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Disclosure of consideration transferred business combinations.

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The amount recognised as of the acquisition date for settlement of stamp duty liability assumed in a business combination.

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