XML 91 R77.htm IDEA: XBRL DOCUMENT v3.21.1
Basis of Preparation and Accounting Policies - Estimated Useful Life of Assets (Detail)
 12 Months Ended
Dec. 31, 2020
Freehold buildings [member]  
Disclosure of detailed information about property, plant and equipment [line items]  
Estimated useful life of Property, plant and equipment 50 years
Leasehold buildings and improvements [member]  
Disclosure of detailed information about property, plant and equipment [line items]  
Description of estimated useful life of Property, plant and equipment Shorter of 15 to 50 years or lease term
Bottom of range [member] | Plant, machinery and equipment [member]  
Disclosure of detailed information about property, plant and equipment [line items]  
Estimated useful life of Property, plant and equipment 3 years
Bottom of range [member] | Office furniture, fittings and equipment [member]  
Disclosure of detailed information about property, plant and equipment [line items]  
Estimated useful life of Property, plant and equipment 3 years
Bottom of range [member] | Motor and transport vehicles [member]  
Disclosure of detailed information about property, plant and equipment [line items]  
Estimated useful life of Property, plant and equipment 3 years 6 months
Top of range [member] | Plant, machinery and equipment [member]  
Disclosure of detailed information about property, plant and equipment [line items]  
Estimated useful life of Property, plant and equipment 20 years
Top of range [member] | Office furniture, fittings and equipment [member]  
Disclosure of detailed information about property, plant and equipment [line items]  
Estimated useful life of Property, plant and equipment 20 years
Top of range [member] | Motor and transport vehicles [member]  
Disclosure of detailed information about property, plant and equipment [line items]  
Estimated useful life of Property, plant and equipment 15 years