Summary of Significant Accounting Policies - Property, Plant and Equipment (Details)	12 Months Ended
	Dec. 31, 2019
Office and technical equipment | Minimum
Estimated Useful Lives
Estimated Useful Lives	3 years
Office and technical equipment | Maximum
Estimated Useful Lives
Estimated Useful Lives	10 years
Computer equipment and software
Estimated Useful Lives
Estimated Useful Lives	3 years
Customer premise equipment
Estimated Useful Lives
Estimated Useful Lives	5 years
Vehicles
Estimated Useful Lives
Estimated Useful Lives	5 years
Telephony infrastructure | Minimum
Estimated Useful Lives
Estimated Useful Lives	5 years
Telephony infrastructure | Maximum
Estimated Useful Lives
Estimated Useful Lives	7 years
Head-end equipment
Estimated Useful Lives
Estimated Useful Lives	7 years
Distribution facilities
Estimated Useful Lives
Estimated Useful Lives	10 years
Buildings and leasehold improvements | Minimum
Estimated Useful Lives
Estimated Useful Lives	5 years
Buildings and leasehold improvements | Maximum
Estimated Useful Lives
Estimated Useful Lives	20 years