Revenue Recognition (Disaggregation Of Revenue) (Details) - USD ($) $ in Millions	3 Months Ended		4 Months Ended	5 Months Ended	9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Apr. 30, 2021	Sep. 30, 2021	Sep. 30, 2022
Successor [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	$ 1,426	$ 1,493		$ 2,499	$ 4,310
Subsidy and other revenue	18	83		138	40
Total revenue	1,444	1,576		2,637	4,350
Successor [Member] | Data And Internet Services [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	848	834		1,390	2,531
Successor [Member] | Voice Services [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	369	411		694	1,136
Successor [Member] | Video Services [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	127	149		254	398
Successor [Member] | Other [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	82	99		161	245
Successor [Member] | Consumer [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	785	800		1,343	2,352
Successor [Member] | Business And Wholesale [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	$ 641	$ 693		$ 1,156	$ 1,958
Predecessor [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers			$ 2,120
Subsidy and other revenue			111
Total revenue			2,231
Predecessor [Member] | Data And Internet Services [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers			1,125
Predecessor [Member] | Voice Services [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers			647
Predecessor [Member] | Video Services [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers			223
Predecessor [Member] | Other [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers			125
Predecessor [Member] | Consumer [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers			1,133
Predecessor [Member] | Business And Wholesale [Member]
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers			$ 987