Segment Information (Details 2) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2017 USD ($)	Jun. 30, 2016 USD ($)	Jun. 30, 2017 USD ($) category	Jun. 30, 2016 USD ($)
Operating revenues by products and services
Number of categories of products and services (categories) | category			4
Revenues	$ 4,090	$ 4,398	$ 8,299	$ 8,799
Surcharge amount on customers' bills	133	144	263	291
Strategic services
Operating revenues by products and services
Revenues	1,915	2,042	3,928	4,043
IT and managed services
Operating revenues by products and services
Revenues	$ 162	161	$ 314	323
Facilities-based video services
Operating revenues by products and services
Number of markets	16		16
Legacy services
Operating revenues by products and services
Revenues	$ 1,740	1,926	$ 3,530	3,902
Data integration
Operating revenues by products and services
Revenues	133	123	251	239
IT and managed services data integration
Operating revenues by products and services
Revenues	9	1	10	1
Other revenues
Operating revenues by products and services
Revenues	302	307	590	615
High cost support revenue
Operating revenues by products and services
Revenues	168	173	336	347
Other revenue
Operating revenues by products and services
Revenues	134	134	254	268
Enterprise
Operating revenues by products and services
Revenues	2,215	2,435	4,571	4,877
Enterprise | Enterprise high-bandwidth data services
Operating revenues by products and services
Revenues	760	753	1,529	1,491
Enterprise | Other enterprise strategic services
Operating revenues by products and services
Revenues	225	328	553	655
Enterprise | Voice services
Operating revenues by products and services
Revenues	558	611	1,131	1,233
Enterprise | Enterprise low-bandwidth data services
Operating revenues by products and services
Revenues	302	352	616	717
Enterprise | Other enterprise legacy services
Operating revenues by products and services
Revenues	247	269	502	544
Enterprise | Data integration
Operating revenues by products and services
Revenues	123	122	240	237
Consumer
Operating revenues by products and services
Revenues	1,402	1,494	2,814	2,983
Consumer | Consumer broadband services
Operating revenues by products and services
Revenues	661	682	1,322	1,349
Consumer | Other consumer strategic services
Operating revenues by products and services
Revenues	107	118	210	225
Consumer | Voice services
Operating revenues by products and services
Revenues	562	615	1,137	1,249
Consumer | Other consumer legacy services
Operating revenues by products and services
Revenues	71	79	144	159
Consumer | Data integration
Operating revenues by products and services
Revenues	$ 1	0	$ 1	1
Other enterprise strategic services | Restatement adjustment | Enterprise | Strategic services
Operating revenues by products and services
Revenues		12		24
Other enterprise legacy services | Restatement adjustment | Enterprise | Legacy services
Operating revenues by products and services
Revenues		$ (12)		$ (24)