XML 44 R20.htm IDEA: XBRL DOCUMENT v2.4.1.9
Basis of Presentation (Details) (USD $)
In Millions, unless otherwise specified
 3 Months Ended
Mar. 31, 2015
Organization, Consolidation and Presentation of Financial Statements [Abstract]  
Unamortized debt issuance expense $ 110us-gaap_UnamortizedDebtIssuanceExpense
Geographic Areas, Revenues from External Customers [Abstract]  
Number of states in which entity operates (states) 14us-gaap_NumberOfStatesInWhichEntityOperates
CenturyLink, Inc. | Maximum | Change in allocation methodology for net periodic benefit service cost  
Change in allocation methodology  
Pension and other postretirement benefit service costs $ 1ctq_PensionandOtherPostretirementBenefitServiceCosts
/ ctq_ChangeinAllocationMethodologybyTypeAxis
= ctq_ChangeinAllocationMethodologyforNetPeriodicBenefitServiceCostMember
/ us-gaap_RangeAxis
= us-gaap_MaximumMember
/ us-gaap_RelatedPartyTransactionsByRelatedPartyAxis
= ctq_CenturyLinkInc.Member