Segment Information - Segment Results and Operating Revenue (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Operating revenues by products and services
Revenues	$ 5,192	$ 5,375	$ 10,420	$ 10,802
Cost of services and products	2,232	2,243	4,467	4,543
Selling, general and administrative	895	960	1,748	1,892
Less: share-based compensation	(20)	(43)	(89)	(76)
Total expense	3,107	3,160	6,126	6,359
Total adjusted EBITDA	2,085	2,215	4,294	4,443
IP and Data Services
Operating revenues by products and services
Revenues	1,592	1,649	3,216	3,309
Transport and Infrastructure
Operating revenues by products and services
Revenues	1,216	1,253	2,448	2,499
Voice and Collaboration
Operating revenues by products and services
Revenues	945	950	1,865	1,917
IT and Managed Services
Operating revenues by products and services
Revenues	123	134	248	279
Broadband
Operating revenues by products and services
Revenues	726	718	1,448	1,440
Voice
Operating revenues by products and services
Revenues	409	467	830	944
Regulatory
Operating revenues by products and services
Revenues	154	157	310	314
Other
Operating revenues by products and services
Revenues	27	47	55	100
Operating segments
Operating revenues by products and services
Revenues	5,192	5,375	10,420	10,802
Cost of services and products	968	959	1,925	1,915
Selling, general and administrative	440	475	883	972
Less: share-based compensation	0	0	0	0
Total expense	1,408	1,434	2,808	2,887
Total adjusted EBITDA	3,784	3,941	7,612	7,915
Operating segments | IP and Data Services
Operating revenues by products and services
Revenues	1,592	1,649	3,216	3,309
Operating segments | Transport and Infrastructure
Operating revenues by products and services
Revenues	1,216	1,253	2,448	2,499
Operating segments | Voice and Collaboration
Operating revenues by products and services
Revenues	945	950	1,865	1,917
Operating segments | IT and Managed Services
Operating revenues by products and services
Revenues	123	134	248	279
Operating segments | Broadband
Operating revenues by products and services
Revenues	726	718	1,448	1,440
Operating segments | Voice
Operating revenues by products and services
Revenues	409	467	830	944
Operating segments | Regulatory
Operating revenues by products and services
Revenues	154	157	310	314
Operating segments | Other
Operating revenues by products and services
Revenues	27	47	55	100
Operating segments | International and Global Accounts
Operating revenues by products and services
Revenues	849	877	1,714	1,740
Cost of services and products	232	232	465	463
Selling, general and administrative	61	67	126	134
Less: share-based compensation	0	0	0	0
Total expense	293	299	591	597
Total adjusted EBITDA	556	578	1,123	1,143
Operating segments | International and Global Accounts | IP and Data Services
Operating revenues by products and services
Revenues	386	409	786	817
Operating segments | International and Global Accounts | Transport and Infrastructure
Operating revenues by products and services
Revenues	311	323	627	632
Operating segments | International and Global Accounts | Voice and Collaboration
Operating revenues by products and services
Revenues	97	89	188	178
Operating segments | International and Global Accounts | IT and Managed Services
Operating revenues by products and services
Revenues	55	56	113	113
Operating segments | International and Global Accounts | Broadband
Operating revenues by products and services
Revenues	0	0	0	0
Operating segments | International and Global Accounts | Voice
Operating revenues by products and services
Revenues	0	0	0	0
Operating segments | International and Global Accounts | Regulatory
Operating revenues by products and services
Revenues	0	0	0	0
Operating segments | International and Global Accounts | Other
Operating revenues by products and services
Revenues	0	0	0	0
Operating segments | Enterprise
Operating revenues by products and services
Revenues	1,433	1,409	2,853	2,834
Cost of services and products	463	434	910	862
Selling, general and administrative	135	141	271	289
Less: share-based compensation	0	0	0	0
Total expense	598	575	1,181	1,151
Total adjusted EBITDA	835	834	1,672	1,683
Operating segments | Enterprise | IP and Data Services
Operating revenues by products and services
Revenues	623	632	1,251	1,270
Operating segments | Enterprise | Transport and Infrastructure
Operating revenues by products and services
Revenues	381	354	761	701
Operating segments | Enterprise | Voice and Collaboration
Operating revenues by products and services
Revenues	371	358	727	724
Operating segments | Enterprise | IT and Managed Services
Operating revenues by products and services
Revenues	58	65	114	139
Operating segments | Enterprise | Broadband
Operating revenues by products and services
Revenues	0	0	0	0
Operating segments | Enterprise | Voice
Operating revenues by products and services
Revenues	0	0	0	0
Operating segments | Enterprise | Regulatory
Operating revenues by products and services
Revenues	0	0	0	0
Operating segments | Enterprise | Other
Operating revenues by products and services
Revenues	0	0	0	0
Operating segments | Small and Medium Business
Operating revenues by products and services
Revenues	646	688	1,304	1,388
Cost of services and products	99	102	203	207
Selling, general and administrative	109	115	219	239
Less: share-based compensation	0	0	0	0
Total expense	208	217	422	446
Total adjusted EBITDA	438	471	882	942
Operating segments | Small and Medium Business | IP and Data Services
Operating revenues by products and services
Revenues	263	271	532	547
Operating segments | Small and Medium Business | Transport and Infrastructure
Operating revenues by products and services
Revenues	91	94	180	189
Operating segments | Small and Medium Business | Voice and Collaboration
Operating revenues by products and services
Revenues	282	312	572	629
Operating segments | Small and Medium Business | IT and Managed Services
Operating revenues by products and services
Revenues	10	11	20	23
Operating segments | Small and Medium Business | Broadband
Operating revenues by products and services
Revenues	0	0	0	0
Operating segments | Small and Medium Business | Voice
Operating revenues by products and services
Revenues	0	0	0	0
Operating segments | Small and Medium Business | Regulatory
Operating revenues by products and services
Revenues	0	0	0	0
Operating segments | Small and Medium Business | Other
Operating revenues by products and services
Revenues	0	0	0	0
Operating segments | Wholesale
Operating revenues by products and services
Revenues	948	1,012	1,906	2,042
Cost of services and products	132	140	263	274
Selling, general and administrative	16	15	33	29
Less: share-based compensation	0	0	0	0
Total expense	148	155	296	303
Total adjusted EBITDA	800	857	1,610	1,739
Operating segments | Wholesale | IP and Data Services
Operating revenues by products and services
Revenues	320	337	647	675
Operating segments | Wholesale | Transport and Infrastructure
Operating revenues by products and services
Revenues	433	482	880	977
Operating segments | Wholesale | Voice and Collaboration
Operating revenues by products and services
Revenues	195	191	378	386
Operating segments | Wholesale | IT and Managed Services
Operating revenues by products and services
Revenues	0	2	1	4
Operating segments | Wholesale | Broadband
Operating revenues by products and services
Revenues	0	0	0	0
Operating segments | Wholesale | Voice
Operating revenues by products and services
Revenues	0	0	0	0
Operating segments | Wholesale | Regulatory
Operating revenues by products and services
Revenues	0	0	0	0
Operating segments | Wholesale | Other
Operating revenues by products and services
Revenues	0	0	0	0
Operating segments | Consumer
Operating revenues by products and services
Revenues	1,316	1,389	2,643	2,798
Cost of services and products	42	51	84	109
Selling, general and administrative	119	137	234	281
Less: share-based compensation	0	0	0	0
Total expense	161	188	318	390
Total adjusted EBITDA	1,155	1,201	2,325	2,408
Operating segments | Consumer | IP and Data Services
Operating revenues by products and services
Revenues	0	0	0	0
Operating segments | Consumer | Transport and Infrastructure
Operating revenues by products and services
Revenues	0	0	0	0
Operating segments | Consumer | Voice and Collaboration
Operating revenues by products and services
Revenues	0	0	0	0
Operating segments | Consumer | IT and Managed Services
Operating revenues by products and services
Revenues	0	0	0	0
Operating segments | Consumer | Broadband
Operating revenues by products and services
Revenues	726	718	1,448	1,440
Operating segments | Consumer | Voice
Operating revenues by products and services
Revenues	409	467	830	944
Operating segments | Consumer | Regulatory
Operating revenues by products and services
Revenues	154	157	310	314
Operating segments | Consumer | Other
Operating revenues by products and services
Revenues	27	47	55	100
Operations and Other
Operating revenues by products and services
Revenues	0	0	0	0
Cost of services and products	1,264	1,284	2,542	2,628
Selling, general and administrative	455	485	865	920
Less: share-based compensation	(20)	(43)	(89)	(76)
Total expense	1,699	1,726	3,318	3,472
Total adjusted EBITDA	(1,699)	(1,726)	(3,318)	(3,472)
Operations and Other | IP and Data Services
Operating revenues by products and services
Revenues	0	0	0	0
Operations and Other | Transport and Infrastructure
Operating revenues by products and services
Revenues	0	0	0	0
Operations and Other | Voice and Collaboration
Operating revenues by products and services
Revenues	0	0	0	0
Operations and Other | IT and Managed Services
Operating revenues by products and services
Revenues	0	0	0	0
Operations and Other | Broadband
Operating revenues by products and services
Revenues	0	0	0	0
Operations and Other | Voice
Operating revenues by products and services
Revenues	0	0	0	0
Operations and Other | Regulatory
Operating revenues by products and services
Revenues	0	0	0	0
Operations and Other | Other
Operating revenues by products and services
Revenues	$ 0	$ 0	$ 0	$ 0