Revenue Recognition (Disaggregation Of Revenue) (Details) - USD ($) $ in Millions	4 Months Ended	8 Months Ended	12 Months Ended
	Apr. 30, 2021	Dec. 31, 2021	Dec. 31, 2023	Dec. 31, 2022
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	$ 2,120	$ 3,958	$ 5,676	$ 5,733
Subsidy and other revenue	111	222	75	54
Total revenue	2,231	4,180	5,751	5,787
Revenue from contracts with customers, performance obligation			806
Data And Internet Services [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	1,125	2,224	3,534	3,390
Voice Services [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	647	1,091	1,373	1,498
Video Services [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	223	397	430	520
Other [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	125	246	339	325
Consumer [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	1,133	2,125	3,097	3,116
Business And Wholesale [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	$ 987	$ 1,833	$ 2,579	$ 2,617