XML 61 R46.htm IDEA: XBRL DOCUMENT
v3.19.3

Revenue Recognition - Additional Information (Details) | 9 Months Ended
--- | ---
Sep. 30, 2019
Minimum |
Revenue, Initial Application Period Cumulative Effect Transition [Line Items] |
Contract term | 1 year
Minimum | Business Customer |
Revenue, Initial Application Period Cumulative Effect Transition [Line Items] |
Length of customer life | 12 months
Maximum |
Revenue, Initial Application Period Cumulative Effect Transition [Line Items] |
Contract term | 7 years
Maximum | Business Customer |
Revenue, Initial Application Period Cumulative Effect Transition [Line Items] |
Length of customer life | 60 months
Weighted Average | Consumer Customers |
Revenue, Initial Application Period Cumulative Effect Transition [Line Items] |
Length of customer life | 30 months

X
- Definition Revenue from Contract with Customer, Contract Term + References No definition available. + Details
Name: | ctl_RevenueFromContractWithCustomerContractTerm
Namespace Prefix: | ctl_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Revenue from Contract with Customer, Length of Customer Life + References No definition available. + Details
Name: | ctl_RevenueFromContractWithCustomerLengthOfCustomerLife
Namespace Prefix: | ctl_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
Name: | us-gaap_RevenueInitialApplicationPeriodCumulativeEffectTransitionLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | srt_RangeAxis=srt_MinimumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_MajorCustomersAxis=ctl_BusinessCustomerMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_RangeAxis=srt_MaximumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_RangeAxis=srt_WeightedAverageMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_MajorCustomersAxis=ctl_ConsumerCustomersMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |