Consolidated Statements Of Operations - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Consolidated Statements Of Operations [Abstract]
Revenue	$ 1,368	$ 1,147	$ 2,739	$ 2,301
Operating expenses:
Network access expenses	161	106	316	213
Network related expenses	313	259	638	522
Selling, general and administrative expenses	331	265	661	531
Depreciation and amortization	335	274	676	555
Acquisition and integration costs	35	19	92	30
Total operating expenses	1,175	923	2,383	1,851
Operating income	193	224	356	450
Investment and other income, net	1		2	1
Interest expense	260	167	505	338
Income (loss) before income taxes	(66)	57	(147)	113
Income tax expense (benefit)	(38)	19	(68)	36
Net income (loss)	$ (28)	$ 38	$ (79)	$ 77
Basic and diluted net income (loss) per common share (in dollars per share)	$ (0.03)	$ 0.04	$ (0.08)	$ 0.08