Acquisitions (Operating Expenses Related To Acquisitions) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Business Acquisition [Line Items]
Acquisition costs	$ 21	$ 2	$ 23	$ 36
Integration costs	106	33	242	56
Total acquisition and integration costs	127	35	265	92
Verizon Transaction [Member]
Business Acquisition [Line Items]
Acquisition costs	21	2	23	35
Integration costs	$ 106	28	$ 242	31
Connecticut Operations [Member]
Business Acquisition [Line Items]
Acquisition costs				1
Integration costs		$ 5		$ 25