Summary of Significant Accounting Policies - Property and Equipment (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Property, Plant and Equipment, Useful Life [Line Items]
Internal use software costs capitalized	$ 2.3	$ 1.4	$ 1.8
Land improvements | Minimum
Property, Plant and Equipment, Useful Life [Line Items]
Estimated useful life of property and equipment	20 years
Land improvements | Maximum
Property, Plant and Equipment, Useful Life [Line Items]
Estimated useful life of property and equipment	30 years
Buildings, building improvements, and leasehold improvements | Minimum
Property, Plant and Equipment, Useful Life [Line Items]
Estimated useful life of property and equipment	3 years
Buildings, building improvements, and leasehold improvements | Maximum
Property, Plant and Equipment, Useful Life [Line Items]
Estimated useful life of property and equipment	40 years
Substation equipment
Property, Plant and Equipment, Useful Life [Line Items]
Estimated useful life of property and equipment	30 years
Data center equipment | Minimum
Property, Plant and Equipment, Useful Life [Line Items]
Estimated useful life of property and equipment	5 years
Data center equipment | Maximum
Property, Plant and Equipment, Useful Life [Line Items]
Estimated useful life of property and equipment	10 years
Vehicles
Property, Plant and Equipment, Useful Life [Line Items]
Estimated useful life of property and equipment	7 years
Core network equipment | Minimum
Property, Plant and Equipment, Useful Life [Line Items]
Estimated useful life of property and equipment	5 years
Core network equipment | Maximum
Property, Plant and Equipment, Useful Life [Line Items]
Estimated useful life of property and equipment	7 years
Cloud computing equipment
Property, Plant and Equipment, Useful Life [Line Items]
Estimated useful life of property and equipment	5 years
Fiber facilities | Minimum
Property, Plant and Equipment, Useful Life [Line Items]
Estimated useful life of property and equipment	20 years
Fiber facilities | Maximum
Property, Plant and Equipment, Useful Life [Line Items]
Estimated useful life of property and equipment	25 years
Computer equipment, furniture and fixtures | Minimum
Property, Plant and Equipment, Useful Life [Line Items]
Estimated useful life of property and equipment	3 years
Computer equipment, furniture and fixtures | Maximum
Property, Plant and Equipment, Useful Life [Line Items]
Estimated useful life of property and equipment	5 years