Investment in Associates and Joint Ventures - Summary of Financial Information of Material Associate Investment (Parenthetical) (Detail)	12 Months Ended
Dec. 31, 2020	Dec. 31, 2019
Barclay associate [member]
Disclosure of associates [line items]
Net asset percentage	19.90%	19.90%

The proportion of ownership interest in an associate attributable to the entity. [Refer: Associates [member]]

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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Reference 2: http://www.xbrl.org/2003/role/disclosureRef
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Reference 3: http://www.xbrl.org/2003/role/disclosureRef
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Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration