Name:	us-gaap_LossContingenciesLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
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Reflects the estimated amount of loss from the specified contingency as of the balance sheet date.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 450
-SubTopic 20
-Section 50
-Paragraph 4
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=82911808&loc=d3e14435-108349

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 450
-SubTopic 20
-Section 50
-Paragraph 9
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=82911808&loc=d3e14557-108349

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 460
-SubTopic 10
-Section 50
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=115931803&loc=d3e12021-110248

Name:	us-gaap_LossContingencyEstimateOfPossibleLoss
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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

The total number of new claims filed pertaining to a loss contingency during the period.

Name:	us-gaap_LossContingencyNewClaimsFiledNumber
Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

Number of another entity's patents that the entity has allegedly infringed.

No definition available.

Name:	us-gaap_LossContingencyPatentsAllegedlyInfringedNumber
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Data Type:	xbrli:integerItemType
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Period Type:	duration

Number of pending claims pertaining to a loss contingency.

Name:	us-gaap_LossContingencyPendingClaimsNumber
Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

Name:	us-gaap_StatutoryAccountingPracticesByJurisdictionAxis=ctl_LouisianaStateCourtMember
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Name:	us-gaap_StatutoryAccountingPracticesByJurisdictionAxis=ctl_LouisianaFederalCourtMember
Namespace Prefix:
Data Type:	na
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Name:	srt_LitigationCaseAxis=ctl_InterexchangeCarriersMember
Namespace Prefix:
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