Revenue Recognition and Deferred Revenue (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020
Contract Assets and Liabilities [Line Items]
Revenues	$ 2,574,882	$ 2,433,986	$ 7,569,711	$ 7,359,221
Contract assets	18,353		$ 18,353		$ 19,959
Customer Contracts | Minimum
Contract Assets and Liabilities [Line Items]
Finite-lived intangible asset, useful life			3 years
Customer Contracts | Maximum
Contract Assets and Liabilities [Line Items]
Finite-lived intangible asset, useful life			5 years
Broadband [Member]
Contract Assets and Liabilities [Line Items]
Revenues	989,410	941,237	$ 2,952,136	2,747,129
Pay TV [Member]
Contract Assets and Liabilities [Line Items]
Revenues	877,422	867,021	2,675,861	2,766,608
Telephony [Member]
Contract Assets and Liabilities [Line Items]
Revenues	99,943	115,995	310,298	358,347
Total Residential Revenue
Contract Assets and Liabilities [Line Items]
Revenues	1,966,775	1,924,253	5,938,295	5,872,084
Business Services and Wholesale [Member]
Contract Assets and Liabilities [Line Items]
Revenues	440,813	362,215	1,180,039	1,092,309
Advertising and News [Member]
Contract Assets and Liabilities [Line Items]
Revenues	143,625	124,177	380,462	326,348
Mobile [Member]
Contract Assets and Liabilities [Line Items]
Revenues	20,456	19,722	60,355	57,944
Products And Services, Other [Member]
Contract Assets and Liabilities [Line Items]
Revenues	3,213	3,619	10,560	10,536
Franchise [Member]
Contract Assets and Liabilities [Line Items]
Franchise fees and other taxes and fees	$ 63,841	$ 63,264	$ 195,735	$ 193,454