Segment Information - Schedule of Segment Results (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Operating revenues by products and services
Segment revenue	$ 3,641	$ 4,390	$ 11,040	$ 13,678
Cost of services and products	1,850	1,999	5,407	6,042
Selling, general and administrative	791	792	2,302	2,407
Operating Segments
Operating revenues by products and services
Segment revenue	3,641	4,390	11,040	13,678
Total segment adjusted EBITDA	2,143	2,810	6,700	8,928
Operating Segments | Business
Operating revenues by products and services
Segment revenue	2,894	3,218	8,747	10,036
Cost of services and products	796	792	2,343	2,449
Selling, general and administrative	324	293	916	928
Total segment expense	1,120	1,085	3,259	3,377
Total segment adjusted EBITDA	1,774	2,133	5,488	6,659
Operating Segments | Mass Markets
Operating revenues by products and services
Segment revenue	747	1,172	2,293	3,642
Cost of services and products	22	25	71	90
Selling, general and administrative	356	470	1,010	1,283
Total segment expense	378	495	1,081	1,373
Total segment adjusted EBITDA	$ 369	$ 677	$ 1,212	$ 2,269