Significant Related Party Transactions - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2020
Domestic [member] | Bottom of range [member]
Disclosure of transactions between related parties [line items]
Collection periods for accounts receivables	month-end 30 days
Domestic [member] | Top of range [member]
Disclosure of transactions between related parties [line items]
Collection periods for accounts receivables	month-end 60 days
Overseas [member] | Bottom of range [member]
Disclosure of transactions between related parties [line items]
Collection periods for accounts receivables	net 30 days
Overseas [member] | Top of range [member]
Disclosure of transactions between related parties [line items]
Collection periods for accounts receivables	net 60 days