Description Of Business And Summary Of Significant Accounting Policies (Narrative) (Details) Customer in Millions, $ in Millions			3 Months Ended								12 Months Ended
	Mar. 16, 2020 USD ($)	Jul. 10, 2017 shares	Dec. 31, 2019 USD ($) Employee State Customer shares	Sep. 30, 2019 USD ($)	Jun. 30, 2019 USD ($)	Mar. 31, 2019 USD ($)	Dec. 31, 2018 USD ($) shares	Sep. 30, 2018 USD ($)	Jun. 30, 2018 USD ($)	Mar. 31, 2018 USD ($)	Dec. 31, 2019 USD ($) Employee segment State Customer shares	Dec. 31, 2018 USD ($) shares	Dec. 31, 2017 USD ($)	Jan. 02, 2019 USD ($)	Jul. 09, 2017 shares
Number of customers | Customer			4.1								4.1
Number of subscribers | Customer			3.5								3.5
Number of employees | Employee			18,300								18,300
Number of states of operation | State			29								29
Reverse stock split, conversion ratio		0.0667
Common stock, shares issued (in shares) | shares		80,000,000	106,025,000				106,025,000				106,025,000	106,025,000
Common stock, shares outstanding (in shares) | shares		79,000,000	105,131,000				105,536,000				105,131,000	105,536,000
Common stock, shares authorized (in shares) | shares		175,000,000	175,000,000				175,000,000				175,000,000	175,000,000
Reverse Stock Split, Fractional Shares Issued | shares		0
Cash and cash equivalents			$ 760				$ 354				$ 760	$ 354
Accumulated deficit			(8,573)				(2,752)				(8,573)	(2,752)		$ (2,741)
Operating loss			220	$ 26	$ (5,459)	$ 339	127	$ (33)	$ 367	$ 366	(4,873)	827	$ (1,483)
Net loss											(5,911)	(643)	(1,804)
Restricted Cash			$ 50								50
Customer surcharges											221	213	216
Video franchise fees											$ 40	47	$ 52
Number of operating regions | segment											1
Expected customer life			4 years								4 years
Number of reporting units | segment											2
Subsequent Event [Member]
Deferred scheduled interest payments	$ 322
Debt repayment grace period	60 days
Subsequent Event [Member] | Minimum [Member]
Percentage of outstanding principal held by holders of the deferred payment senior notes	25.00%
Previously Reported [Member]
Common stock, shares issued (in shares) | shares															1,193,000,000
Common stock, shares outstanding (in shares) | shares															1,178,000,000
Common stock, shares authorized (in shares) | shares															1,750,000,000
Accumulated deficit							$ (2,752)					$ (2,752)