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Property, Plant and Equipment - Estimated Service Lives of Property, Plant and Equipment - Asset Used by The Company (Detail)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Land improvements [Member] | Bottom of Range [Member]
Disclosure Of Property Plant And Equipment [Line Items]
Estimated service lives			P8Y
Land improvements [Member] | Bottom of Range [Member] | Assets Used by the Company [Member]
Disclosure Of Property Plant And Equipment [Line Items]
Estimated service lives	P10Y	P10Y
Land improvements [Member] | Top of Range [Member]
Disclosure Of Property Plant And Equipment [Line Items]
Estimated service lives			P30Y
Land improvements [Member] | Top of Range [Member] | Assets Used by the Company [Member]
Disclosure Of Property Plant And Equipment [Line Items]
Estimated service lives	P30Y	P30Y
Main buildings [Member] | Bottom of Range [Member]
Disclosure Of Property Plant And Equipment [Line Items]
Estimated service lives			P35Y
Main buildings [Member] | Bottom of Range [Member] | Assets Used by the Company [Member]
Disclosure Of Property Plant And Equipment [Line Items]
Estimated service lives	P20Y	P20Y
Main buildings [Member] | Top of Range [Member]
Disclosure Of Property Plant And Equipment [Line Items]
Estimated service lives			P60Y
Main buildings [Member] | Top of Range [Member] | Assets Used by the Company [Member]
Disclosure Of Property Plant And Equipment [Line Items]
Estimated service lives	P60Y	P60Y
Other building facilities [Member] | Bottom of Range [Member]
Disclosure Of Property Plant And Equipment [Line Items]
Estimated service lives			P3Y
Other building facilities [Member] | Bottom of Range [Member] | Assets Used by the Company [Member]
Disclosure Of Property Plant And Equipment [Line Items]
Estimated service lives	P3Y	P3Y
Other building facilities [Member] | Top of Range [Member]
Disclosure Of Property Plant And Equipment [Line Items]
Estimated service lives			P20Y
Other building facilities [Member] | Top of Range [Member] | Assets Used by the Company [Member]
Disclosure Of Property Plant And Equipment [Line Items]
Estimated service lives	P15Y	P15Y
Computer equipment [Member] | Bottom of Range [Member]
Disclosure Of Property Plant And Equipment [Line Items]
Estimated service lives			P2Y
Computer equipment [Member] | Bottom of Range [Member] | Assets Used by the Company [Member]
Disclosure Of Property Plant And Equipment [Line Items]
Estimated service lives	P2Y	P2Y
Computer equipment [Member] | Top of Range [Member]
Disclosure Of Property Plant And Equipment [Line Items]
Estimated service lives			P8Y
Computer equipment [Member] | Top of Range [Member] | Assets Used by the Company [Member]
Disclosure Of Property Plant And Equipment [Line Items]
Estimated service lives	P8Y	P8Y
Telecommunication circuits [Member] | Bottom of Range [Member]
Disclosure Of Property Plant And Equipment [Line Items]
Estimated service lives			P2Y
Telecommunication circuits [Member] | Bottom of Range [Member] | Assets Used by the Company [Member]
Disclosure Of Property Plant And Equipment [Line Items]
Estimated service lives	P2Y	P2Y
Telecommunication circuits [Member] | Top of Range [Member]
Disclosure Of Property Plant And Equipment [Line Items]
Estimated service lives			P30Y
Telecommunication circuits [Member] | Top of Range [Member] | Assets Used by the Company [Member]
Disclosure Of Property Plant And Equipment [Line Items]
Estimated service lives	P30Y	P30Y
Telecommunication machinery and antennas equipment [Member] | Bottom of Range [Member]
Disclosure Of Property Plant And Equipment [Line Items]
Estimated service lives			P2Y
Telecommunication machinery and antennas equipment [Member] | Bottom of Range [Member] | Assets Used by the Company [Member]
Disclosure Of Property Plant And Equipment [Line Items]
Estimated service lives	P2Y	P2Y
Telecommunication machinery and antennas equipment [Member] | Top of Range [Member]
Disclosure Of Property Plant And Equipment [Line Items]
Estimated service lives			P30Y
Telecommunication machinery and antennas equipment [Member] | Top of Range [Member] | Assets Used by the Company [Member]
Disclosure Of Property Plant And Equipment [Line Items]
Estimated service lives	P30Y	P30Y
Transportation equipment [Member] | Bottom of Range [Member]
Disclosure Of Property Plant And Equipment [Line Items]
Estimated service lives			P3Y
Transportation equipment [Member] | Bottom of Range [Member] | Assets Used by the Company [Member]
Disclosure Of Property Plant And Equipment [Line Items]
Estimated service lives	P3Y	P3Y
Transportation equipment [Member] | Top of Range [Member]
Disclosure Of Property Plant And Equipment [Line Items]
Estimated service lives			P10Y
Transportation equipment [Member] | Top of Range [Member] | Assets Used by the Company [Member]
Disclosure Of Property Plant And Equipment [Line Items]
Estimated service lives	P10Y	P10Y
Leasehold improvements [Member] | Bottom of Range [Member]
Disclosure Of Property Plant And Equipment [Line Items]
Estimated service lives			P1Y
Leasehold improvements [Member] | Bottom of Range [Member] | Assets Used by the Company [Member]
Disclosure Of Property Plant And Equipment [Line Items]
Estimated service lives	P1Y	P1Y
Leasehold improvements [Member] | Top of Range [Member]
Disclosure Of Property Plant And Equipment [Line Items]
Estimated service lives			P6Y
Leasehold improvements [Member] | Top of Range [Member] | Assets Used by the Company [Member]
Disclosure Of Property Plant And Equipment [Line Items]
Estimated service lives	P9Y	P9Y
Mechanical and air conditioner equipment [Member] | Bottom of Range [Member]
Disclosure Of Property Plant And Equipment [Line Items]
Estimated service lives			P3Y
Mechanical and air conditioner equipment [Member] | Bottom of Range [Member] | Assets Used by the Company [Member]
Disclosure Of Property Plant And Equipment [Line Items]
Estimated service lives	P3Y	P3Y
Mechanical and air conditioner equipment [Member] | Top of Range [Member]
Disclosure Of Property Plant And Equipment [Line Items]
Estimated service lives			P16Y
Mechanical and air conditioner equipment [Member] | Top of Range [Member] | Assets Used by the Company [Member]
Disclosure Of Property Plant And Equipment [Line Items]
Estimated service lives	P16Y	P16Y
Others [Member] | Bottom of Range [Member]
Disclosure Of Property Plant And Equipment [Line Items]
Estimated service lives			P1Y
Others [Member] | Bottom of Range [Member] | Assets Used by the Company [Member]
Disclosure Of Property Plant And Equipment [Line Items]
Estimated service lives	P1Y	P1Y
Others [Member] | Top of Range [Member]
Disclosure Of Property Plant And Equipment [Line Items]
Estimated service lives			P10Y
Others [Member] | Top of Range [Member] | Assets Used by the Company [Member]
Disclosure Of Property Plant And Equipment [Line Items]
Estimated service lives	P15Y	P15Y

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Useful lives and depreciation rates of property plant and equipment.

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Line items represent concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes of the table.

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