v3.10.0.1

Derivative Instruments (Narrative) (Details) - USD ($) $ in Millions | 12 Months Ended |
--- | --- | ---
Dec. 31, 2018 | Dec. 31, 2017 | Dec. 31, 2016 | May 22, 2018
Derivative [Line Items] |  |  |  |
Gain (loss) on change in credit risk valuation included in realized and unrealized gains (losses) on derivative instruments, net | $ (71.1) | $ 168.4 | $ 26.5 |
Assets - derivative instruments | 2,496.7 | 2,127.7 |  |
Virgin Media |  |  |  |
Derivative [Line Items] |  |  |  |
Notional amount of derivative instruments without exchange of notional amounts at inception and maturity | 4,700.0 |  |  |
Cross Currency Interest Rate Contract |  |  |  |
Derivative [Line Items] |  |  |  |
Assets - derivative instruments | 1,742.8 | $ 1,548.9 |  |
ITV Collar |  |  |  |
Derivative [Line Items] |  |  |  |
Derivative asset fair value | $ 704.0 |  |  |
Number of common stock shares owned (in shares) | 398,515,510 |  |  |
Shares needed to borrow from custody account to hedge exposure (in shares) | 400,000,000 |  |  |
Sumitomo Collar |  |  |  |
Derivative [Line Items] |  |  |  |
Aggregate market value of borrowed Sumitomo shares |  |  |  | $ 159.3
Lionsgate Loan | Common Stock |  |  |  |
Derivative [Line Items] |  |  |  |
Number of common stock shares owned (in shares) | 1,250,000 |  |  |
Lionsgate Loan | Nonvoting Common Stock |  |  |  |
Derivative [Line Items] |  |  |  |
Number of common stock shares owned (in shares) | 1,250,000 |  |  |
Lionsgate Forward |  |  |  |
Derivative [Line Items] |  |  |  |
Derivative asset fair value | $ 42.2 |  |  |
Counterparty Credit Risk |  |  |  |
Derivative [Line Items] |  |  |  |
Assets - derivative instruments | $ 617.3 |  |  |

X
- Definition Gain Loss On Credit Risk Derivatives Net Recognized In Earnings + References No definition available. + Details
Name: | lbtya_GainLossOnCreditRiskDerivativesNetRecognizedInEarnings
Namespace Prefix: | lbtya_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Notional Amount of Derivative Instruments without Exchange of Notional Amounts at Inception and Maturity + References No definition available. + Details
Name: | lbtya_NotionalAmountofDerivativeInstrumentswithoutExchangeofNotionalAmountsatInceptionandMaturity
Namespace Prefix: | lbtya_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Shares Needed to Borrow from Custody Account to Hedge Exposure + References No definition available. + Details
Name: | lbtya_SharesNeededtoBorrowfromCustodyAccounttoHedgeExposure
Namespace Prefix: | lbtya_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | instant

X
- Definition Fair value, after the effects of master netting arrangements, of a financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes assets not subject to a master netting arrangement and not elected to be offset. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 20 -Section 55 -Paragraph 10 -URI http://asc.fasb.org/extlink&oid=99393222&loc=SL20226008-175313 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 825 -SubTopic 10 -Section 50 -Paragraph 10 -URI http://asc.fasb.org/extlink&oid=109250915&loc=d3e13433-108611 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 20 -Section 50 -Paragraph 3 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=51824906&loc=SL20225862-175312 + Details
Name: | us-gaap_DerivativeAssets
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Fair value, before effects of master netting arrangements, of a financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes assets elected not to be offset. Excludes assets not subject to a master netting arrangement. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 20 -Section 55 -Paragraph 7 -URI http://asc.fasb.org/extlink&oid=99393222&loc=SL20226000-175313 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 860 -SubTopic 20 -Section 50 -Paragraph 4D -Subparagraph (c)(2) -URI http://asc.fasb.org/extlink&oid=109247956&loc=SL51823488-111719 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 20 -Section 50 -Paragraph 3 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=51824906&loc=SL20225862-175312 Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4B -Subparagraph (a),(c) -URI http://asc.fasb.org/extlink&oid=109980867&loc=SL5624163-113959 + Details
Name: | us-gaap_DerivativeFairValueOfDerivativeAsset
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

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_DerivativeLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Balance held at close of period in number of shares. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 946 -SubTopic 210 -Section 50 -Paragraph 6 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=99383244&loc=d3e12121-115841 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 946 -SubTopic 320 -Section S99 -Paragraph 6 -Subparagraph (SX 210.12-14.Column B) -URI http://asc.fasb.org/extlink&oid=50485924&loc=d3e611322-123010 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 946 -SubTopic 320 -Section S99 -Paragraph 4 -Subparagraph (SX 210.12-12C.Column B) -URI http://asc.fasb.org/extlink&oid=50485924&loc=d3e611225-123010 Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 946 -SubTopic 320 -Section S99 -Paragraph 1 -Subparagraph (SX 210.12-12.Column B) -URI http://asc.fasb.org/extlink&oid=50485924&loc=d3e611133-123010 + Details
Name: | us-gaap_InvestmentOwnedBalanceShares
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | instant

X
- Definition Market value of securities borrowed to the extent to which no equivalent value is paid or credited. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher SEC -Name Rule 15c3-1 -Number 240 -Section 15c3-1 + Details
Name: | us-gaap_SecuritiesBorrowedForWhichNoValueIsPaidOrCredited
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Details
Name: | dei_LegalEntityAxis=lbtya_VirginMediaMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=us-gaap_CrossCurrencyInterestRateContractMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=lbtya_ITVCollarMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=lbtya_SumitomoCollarMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=lbtya_LionsgateLoanMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementClassOfStockAxis=us-gaap_CommonStockMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementClassOfStockAxis=us-gaap_NonvotingCommonStockMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=lbtya_LionsgateForwardMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=lbtya_CounterpartyCreditRiskMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |