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Financial instruments - Summary of key Assumptions used to Determine the Fair Value of Assets Held For Sale (Detail) - Assets Held for Sale
12 Months Ended
Dec. 31, 2020
USD ($)
Sale Price  
Disclosure Of Information About Key Assumptions Used To Determine The Fair Value Of Assets Held For Sale Explanatory [Line Items]  
Unobservable input Sales price
Value assigned to key assumption $ 145,399
Approach to determining key assumption Average of purchase proposals received
Cost of Disposal  
Disclosure Of Information About Key Assumptions Used To Determine The Fair Value Of Assets Held For Sale Explanatory [Line Items]  
Unobservable input Cost of disposal
Value assigned to key assumption $ (9,857)
Approach to determining key assumption Estimated based on the Company’s experience with disposal of similar assets.