Income Taxes (Details 2) (USD $) In Millions, unless otherwise specified	12 Months Ended			12 Months Ended			1 Months Ended
	Dec. 31, 2012	Dec. 31, 2012 Savvis	Jul. 15, 2011 Savvis	Dec. 31, 2012 Qwest	Dec. 31, 2011 Qwest	Apr. 02, 2011 Qwest	Oct. 31, 2011 Embarq Corporation	Dec. 31, 2012 Investment tax credits	Dec. 31, 2012 Investment tax credits State Jurisdiction	Dec. 31, 2012 Alternative minimum tax credits
Income taxes
Net current deferred tax asset recognized in connection with Qwest acquisition						$ 271
Tax credit carryforwards									72	62
Tax credit carryforwards, net of federal income tax								47
Deferred tax asset valuation allowance adjustment	(12)	10		248
Net noncurrent deferred tax liabilities			320			595
Settlement recorded upon dismissal of refund appeal							242
Settlement decrease in unrecognized tax benefits due to withdrawal of Qwest's claims associated with the treatment of universal services fund receipts					$ 141