XML 137 R118.htm IDEA: XBRL DOCUMENT v3.21.1
Investment Properties - Investment Properties Depreciated on a Straight-Line Basis Over Useful Lives (Detail)
12 Months Ended
Dec. 31, 2020
Bottom of range [member] | Main plant buildings [Member]  
Disclosure of detailed information about investment property [line items]  
Investment properties are depreciated using the straight-line method over their estimated useful lives 10
Bottom of range [member] | Right-of-use assets [member]  
Disclosure of detailed information about investment property [line items]  
Investment properties are depreciated using the straight-line method over their estimated useful lives 15
Top of range [member] | Main plant buildings [Member]  
Disclosure of detailed information about investment property [line items]  
Investment properties are depreciated using the straight-line method over their estimated useful lives 40
Top of range [member] | Right-of-use assets [member]  
Disclosure of detailed information about investment property [line items]  
Investment properties are depreciated using the straight-line method over their estimated useful lives 50