Segment Information (Details 2) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2015 USD ($)	Sep. 30, 2015 USD ($)	Jun. 30, 2015 USD ($)	Mar. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)	Sep. 30, 2014 USD ($)	Jun. 30, 2014 USD ($)	Mar. 31, 2014 USD ($)	Dec. 31, 2015 USD ($) category	Dec. 31, 2014 USD ($)	Dec. 31, 2013 USD ($)
Operating revenues by products and services
Operating revenues	$ 4,476	$ 4,554	$ 4,419	$ 4,451	$ 4,438	$ 4,514	$ 4,541	$ 4,538	$ 17,900	$ 18,031	$ 18,095
Surcharge amount on customers' bills									$ 544	526	489
Number of categories of products and services (categories) | category									4
Strategic services
Operating revenues by products and services
Operating revenues									$ 9,343	9,166	8,776
Strategic services | Products and services revenue reclassification | Restatement adjustment
Operating revenues by products and services
Operating revenues										(34)	(47)
Facilities-based video services
Operating revenues by products and services
Number of markets	16								16
Legacy services
Operating revenues by products and services
Operating revenues									$ 6,752	7,172	7,663
Legacy services | Products and services revenue reclassification | Restatement adjustment
Operating revenues by products and services
Operating revenues										34	47
Data integration
Operating revenues by products and services
Operating revenues									573	690	656
High-cost support revenue
Operating revenues by products and services
Operating revenues									732	528	547
Other revenue
Operating revenues by products and services
Operating revenues									500	475	453
Total other revenues
Operating revenues by products and services
Operating revenues									1,232	1,003	1,000
Business
Operating revenues by products and services
Operating revenues									10,647	11,034	11,091
Business | Data integration
Operating revenues by products and services
Operating revenues									571	686	651
Business | High-bandwidth data services
Operating revenues by products and services
Operating revenues									2,816	2,579	2,230
Business | Low-bandwidth data services
Operating revenues by products and services
Operating revenues									2,052	2,345	2,577
Business | Hosting services
Operating revenues by products and services
Operating revenues									1,281	1,316	1,259
Business | Other business strategic services
Operating revenues by products and services
Operating revenues									162	76	60
Business | Voice services
Operating revenues by products and services
Operating revenues									2,590	2,780	2,916
Business | Other business legacy services
Operating revenues by products and services
Operating revenues									1,175	1,252	1,398
Consumer
Operating revenues by products and services
Operating revenues									6,021	5,994	6,004
Consumer | Data integration
Operating revenues by products and services
Operating revenues									2	4	5
Consumer | High-speed Internet services
Operating revenues by products and services
Operating revenues									2,611	2,469	2,358
Consumer | Other consumer strategic services
Operating revenues by products and services
Operating revenues									421	381	292
Consumer | Voice services
Operating revenues by products and services
Operating revenues									2,676	2,864	3,101
Consumer | Other consumer legacy services
Operating revenues by products and services
Operating revenues									$ 311	$ 276	$ 248