Property, Plant and Equipment-Asset Retirement Obligation (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Asset Retirement Obligation
Balance at beginning of year	$ 106	$ 109	$ 41
Accretion expense	7	7	9
Liabilities incurred	0	1	0
Liabilities assumed in Qwest and Savvis acquisitions	0	0	124
Liabilities settled and other	(4)	(1)	(3)
Change in estimate	(3)	(10)	(62)
Balance at end of year	$ 106	$ 106	$ 109