Summary Of Significant Accounting Policies (Narrative) (Details) $ in Millions	3 Months Ended
	Mar. 31, 2023 USD ($) segment	Mar. 31, 2022 USD ($)	Dec. 31, 2022 USD ($)
Description Of Business And Summary Of Significant Accounting Policies [Line Items]
Annual support accepted for commitment for RDOF	$ 37
Number of reportable segments | segment	1
Short-term Investments	$ 900		$ 1,750
Lease Impairment		$ 44
Revenue recognition period, FCC's CAF Phase II subsidies	7 years
Provided funding period, for construction of broadband networks	10 years
Business And Wholesale [Member] | Minimum [Member]
Description Of Business And Summary Of Significant Accounting Policies [Line Items]
Useful life	11 years
Business And Wholesale [Member] | Maximum [Member]
Description Of Business And Summary Of Significant Accounting Policies [Line Items]
Useful life	16 years
Trademarks and Tradenames [Member]
Description Of Business And Summary Of Significant Accounting Policies [Line Items]
Useful life	5 years