Summary of Significant Accounting Policies - Summary of Estimated Lives Used in Determining Depreciation (Detail)	12 Months Ended
	Dec. 31, 2015
Buildings
Property, Plant and Equipment [Line Items]
Estimated useful life of intangible assets (in years)	30 years
Minimum | Network equipment, computers and software
Property, Plant and Equipment [Line Items]
Estimated useful life of intangible assets (in years)	3 years
Minimum | Leasehold improvements
Property, Plant and Equipment [Line Items]
Estimated useful life of intangible assets (in years)	3 years
Minimum | Office furniture and equipment
Property, Plant and Equipment [Line Items]
Estimated useful life of intangible assets (in years)	3 years
Minimum | Motor vehicles
Property, Plant and Equipment [Line Items]
Estimated useful life of intangible assets (in years)	2 years
Maximum | Network equipment, computers and software
Property, Plant and Equipment [Line Items]
Estimated useful life of intangible assets (in years)	5 years
Maximum | Leasehold improvements
Property, Plant and Equipment [Line Items]
Estimated useful life of intangible assets (in years)	8 years
Maximum | Office furniture and equipment
Property, Plant and Equipment [Line Items]
Estimated useful life of intangible assets (in years)	8 years
Maximum | Motor vehicles
Property, Plant and Equipment [Line Items]
Estimated useful life of intangible assets (in years)	5 years