Summary of Significant Accounting Policies Summary of Significant Accounting Policies - Schedule of Property and Equipment, Estimated Useful Lives (Details)	12 Months Ended
	Dec. 31, 2017
Buildings
Property, Plant and Equipment [Line Items]
Estimated useful life	30 years
Minimum | Network equipment and computers
Property, Plant and Equipment [Line Items]
Estimated useful life	3 years
Minimum | Software
Property, Plant and Equipment [Line Items]
Estimated useful life	3 years
Minimum | Leasehold improvements
Property, Plant and Equipment [Line Items]
Estimated useful life	3 years
Minimum | Office furniture and equipment
Property, Plant and Equipment [Line Items]
Estimated useful life	3 years
Minimum | Motor vehicles
Property, Plant and Equipment [Line Items]
Estimated useful life	2 years
Maximum | Network equipment and computers
Property, Plant and Equipment [Line Items]
Estimated useful life	5 years
Maximum | Software
Property, Plant and Equipment [Line Items]
Estimated useful life	5 years
Maximum | Leasehold improvements
Property, Plant and Equipment [Line Items]
Estimated useful life	8 years
Maximum | Office furniture and equipment
Property, Plant and Equipment [Line Items]
Estimated useful life	8 years
Maximum | Motor vehicles
Property, Plant and Equipment [Line Items]
Estimated useful life	5 years