Acquisitions (Narrative) (Details) item in Millions, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2015 USD ($) item	Jun. 30, 2014 USD ($)	Jun. 30, 2015 USD ($) item	Jun. 30, 2014 USD ($)	Dec. 31, 2014 USD ($)
Business Acquisition [Line Items]
Acquisition and integration costs	$ 35	$ 19	$ 92	$ 30
Capital expenditures - Integration activities			(38)	(42)
Revenue	1,368	1,147	2,739	2,301
Operating income	193	$ 224	356	450
Goodwill	7,234		7,234		$ 7,205
Connecticut Operations [Member]
Business Acquisition [Line Items]
Acquisition purchase price	2,018		2,018
Acquisition and integration costs			26	30
Acquisition costs			1	1
Integration costs			25	29
Capital expenditures - Integration activities			19	$ 42
Revenue			528
Operating income			47
Goodwill	883		883
Verizon Transaction [Member]
Business Acquisition [Line Items]
Acquisition purchase price	$ 10,540		10,540
Acquisition and integration costs			66
Acquisition costs			34
Capital expenditures - Integration activities			$ 19
Number of voice connections acquired | item	3.7		3.7
Number of broadband connections acquired | item	2.2		2.2
Number of video connections acquired | item	1.2		1.2
Proceeds from Issuance or Sale of Equity			$ 2,750
Other Acquisitions [Member]
Business Acquisition [Line Items]
Acquisition purchase price	$ 16		16
Goodwill	$ 13		$ 13