Annual report pursuant to Section 13 and 15(d)

Debt (Details 3)

v2.4.1.9
Debt (Details 3) (USD $)
 3 Months Ended 12 Months Ended 0 Months Ended 1 Months Ended 0 Months Ended 3 Months Ended 0 Months Ended
Dec. 31, 2013
Dec. 31, 2014
Dec. 31, 2013
item
Dec. 31, 2012
Apr. 30, 2013
Oct. 31, 2014
Oct. 31, 2013
Jun. 30, 2013
Aug. 31, 2008
Jun. 30, 2013
Oct. 17, 2013
May 01, 2013
Aug. 31, 2013
Sep. 30, 2013
May 31, 2014
Debt Instrument [Line Items]                              
Long-term Debt $ 5,555,000,000us-gaap_LongTermDebt $ 5,852,000,000us-gaap_LongTermDebt $ 5,555,000,000us-gaap_LongTermDebt                        
Warrant expiration period   81 days                          
Borrowings of debt   2,758,000,000us-gaap_ProceedsFromIssuanceOfLongTermDebt 5,923,000,000us-gaap_ProceedsFromIssuanceOfLongTermDebt                        
Class of Warrant or Right, Exercise Price of Warrants or Rights                     $ 255.64us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1        
Class of Warrant or Right, Exercise Price of Warrants or Rights                     $ 255.64us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1        
Proceeds from Issuance of Warrants 170,000,000us-gaap_ProceedsFromIssuanceOfWarrants   170,000,000us-gaap_ProceedsFromIssuanceOfWarrants                        
Repayments of Long-term Debt   1,936,000,000us-gaap_RepaymentsOfLongTermDebt 2,779,000,000us-gaap_RepaymentsOfLongTermDebt 750,000,000us-gaap_RepaymentsOfLongTermDebt                      
Number of margin loans     3lmca_NumberOfMarginLoans                        
Debt Conversion of a Consolidated Subsidiary, Shares received upon maturity of exchangeable note   5,974,510lmca_DebtConversionOfConsolidatedSubsidiarySharesReceivedUponMaturityOfExchangeableNote                          
Sirius XM credit facility                              
Debt Instrument [Line Items]                              
Long-term Debt 460,000,000us-gaap_LongTermDebt
/ us-gaap_LongtermDebtTypeAxis
= lmca_SiriusXmCreditFacilityMember 		380,000,000us-gaap_LongTermDebt
/ us-gaap_LongtermDebtTypeAxis
= lmca_SiriusXmCreditFacilityMember 		460,000,000us-gaap_LongTermDebt
/ us-gaap_LongtermDebtTypeAxis
= lmca_SiriusXmCreditFacilityMember 		                       
Line of Credit Facility, Remaining Borrowing Capacity   870,000,000us-gaap_LineOfCreditFacilityRemainingBorrowingCapacity
/ us-gaap_LongtermDebtTypeAxis
= lmca_SiriusXmCreditFacilityMember 		                         
Debt Instrument, Term   5 years                          
Line of Credit Facility, Maximum Borrowing Capacity   1,250,000,000us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity
/ us-gaap_LongtermDebtTypeAxis
= lmca_SiriusXmCreditFacilityMember 		                         
1.375% Cash Convertible Senior Notes due 2023                              
Debt Instrument [Line Items]                              
Debt face amount                     1,000,000,000us-gaap_DebtInstrumentFaceAmount
/ us-gaap_DebtInstrumentAxis
= lmca_A1.375CashConvertibleSeniorNotesdue2023Member 		       
Debt Instrument, Interest Rate, Stated Percentage   1.375%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ us-gaap_DebtInstrumentAxis
= lmca_A1.375CashConvertibleSeniorNotesdue2023Member 		                         
Debt instrument, face amount per debenture                     1,000lmca_DebtInstrumentFaceAmountPerDebenture
/ us-gaap_DebtInstrumentAxis
= lmca_A1.375CashConvertibleSeniorNotesdue2023Member 		       
Debt Instrument, Convertible, Threshold Trading Days   20us-gaap_DebtInstrumentConvertibleThresholdTradingDays
/ us-gaap_DebtInstrumentAxis
= lmca_A1.375CashConvertibleSeniorNotesdue2023Member 		                         
Debt Instrument, Convertible, Threshold Consecutive Trading Days   30 days                          
Debt instrument, convertible, threshold percentage of conversion price to stock price trigger   130.00%lmca_Debtinstrumentconvertiblethresholdpercentageofconversionpricetostockpricetrigger
/ us-gaap_DebtInstrumentAxis
= lmca_A1.375CashConvertibleSeniorNotesdue2023Member 		                         
Number of business days in measurement period   5lmca_DebtInstrumentConvertibleMeasurementPeriodBusinessDays
/ us-gaap_DebtInstrumentAxis
= lmca_A1.375CashConvertibleSeniorNotesdue2023Member 		                         
Number of consecutive trading days in measurement period.   5 days                          
Debt Instrument, Convertible, Threshold Percentage of Stock Price Trigger   98.00%us-gaap_DebtInstrumentConvertibleThresholdPercentageOfStockPriceTrigger
/ us-gaap_DebtInstrumentAxis
= lmca_A1.375CashConvertibleSeniorNotesdue2023Member 		                         
Proceeds from (Payments for) Other Financing Activities 871,000,000us-gaap_ProceedsFromDebtNetOfIssuanceCosts
/ us-gaap_DebtInstrumentAxis
= lmca_A1.375CashConvertibleSeniorNotesdue2023Member 		                           
$1 billion margin loan due 2014 | Term loan                              
Debt Instrument [Line Items]                              
Borrowings of debt         250,000,000us-gaap_ProceedsFromIssuanceOfLongTermDebt
/ us-gaap_DebtInstrumentAxis
= lmca_A1billionmarginloandue2014Member
/ us-gaap_LongtermDebtTypeAxis
= lmca_TermloanMember 		                   
Debt Instrument, Description of Variable Rate Basis   LIBOR                          
Debt Instrument, Basis Spread on Variable Rate   2.00%us-gaap_DebtInstrumentBasisSpreadOnVariableRate1
/ us-gaap_DebtInstrumentAxis
= lmca_A1billionmarginloandue2014Member
/ us-gaap_LongtermDebtTypeAxis
= lmca_TermloanMember 		                         
$1 billion margin loan due 2014 | Revolving Credit Facility                              
Debt Instrument [Line Items]                              
Borrowings of debt         450,000,000us-gaap_ProceedsFromIssuanceOfLongTermDebt
/ us-gaap_DebtInstrumentAxis
= lmca_A1billionmarginloandue2014Member
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_RevolvingCreditFacilityMember 		                   
Repayments of Long-term Debt 200,000,000us-gaap_RepaymentsOfLongTermDebt
/ us-gaap_DebtInstrumentAxis
= lmca_A1billionmarginloandue2014Member
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_RevolvingCreditFacilityMember 		          200,000,000us-gaap_RepaymentsOfLongTermDebt
/ us-gaap_DebtInstrumentAxis
= lmca_A1billionmarginloandue2014Member
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_RevolvingCreditFacilityMember 		250,000,000us-gaap_RepaymentsOfLongTermDebt
/ us-gaap_DebtInstrumentAxis
= lmca_A1billionmarginloandue2014Member
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_RevolvingCreditFacilityMember 		             
Debt Instrument, Description of Variable Rate Basis           LIBOR                  
Line of Credit Facility, Remaining Borrowing Capacity   750,000,000us-gaap_LineOfCreditFacilityRemainingBorrowingCapacity
/ us-gaap_DebtInstrumentAxis
= lmca_A1billionmarginloandue2014Member
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_RevolvingCreditFacilityMember 		                         
Incremental borrowing capacity   1,000,000,000lmca_IncrementalBorrowingCapacity
/ us-gaap_DebtInstrumentAxis
= lmca_A1billionmarginloandue2014Member
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_RevolvingCreditFacilityMember 		                         
$1 billion margin loan due 2015 Member | Term loan                              
Debt Instrument [Line Items]                              
Debt face amount           250,000,000us-gaap_DebtInstrumentFaceAmount
/ us-gaap_DebtInstrumentAxis
= lmca_OneBillionMarginLoanDue2015Member
/ us-gaap_LongtermDebtTypeAxis
= lmca_TermloanMember 		                 
$1 billion margin loan due 2015 Member | Revolving Credit Facility                              
Debt Instrument [Line Items]                              
Debt face amount           750,000,000us-gaap_DebtInstrumentFaceAmount
/ us-gaap_DebtInstrumentAxis
= lmca_OneBillionMarginLoanDue2015Member
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_RevolvingCreditFacilityMember 		                 
Interest rate at year end   1.98%us-gaap_DebtInstrumentInterestRateEffectivePercentage
/ us-gaap_DebtInstrumentAxis
= lmca_OneBillionMarginLoanDue2015Member
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_RevolvingCreditFacilityMember 		                         
Debt instrument, basis spread on variable rate, floor           1.75%lmca_DebtInstrumentBasisSpreadOnVariableRateFloor
/ us-gaap_DebtInstrumentAxis
= lmca_OneBillionMarginLoanDue2015Member
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_RevolvingCreditFacilityMember 		                 
Debt instrument, basis spread on variable rate, cap           2.50%lmca_DebtInstrumentBasisSpreadOnVariableRateCap
/ us-gaap_DebtInstrumentAxis
= lmca_OneBillionMarginLoanDue2015Member
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_RevolvingCreditFacilityMember 		                 
Debt instrument, unused borrowing capacity, fee, percent           0.75%lmca_DebtInstrumentUnusedBorrowingCapacityFeePercent
/ us-gaap_DebtInstrumentAxis
= lmca_OneBillionMarginLoanDue2015Member
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_RevolvingCreditFacilityMember 		                 
$670 million margin loan due 2015                              
Debt Instrument [Line Items]                              
Debt face amount                       670,000,000us-gaap_DebtInstrumentFaceAmount
/ us-gaap_DebtInstrumentAxis
= lmca_A670millionmarginloandue2015Member 		     
Repayments of Long-term Debt   670,000,000us-gaap_RepaymentsOfLongTermDebt
/ us-gaap_DebtInstrumentAxis
= lmca_A670millionmarginloandue2015Member 		                         
Debt Instrument, Basis Spread on Variable Rate   3.25%us-gaap_DebtInstrumentBasisSpreadOnVariableRate1
/ us-gaap_DebtInstrumentAxis
= lmca_A670millionmarginloandue2015Member 		                         
Sirius XM 7% Exchangeable Senior Subordinated Notes due 2014                              
Debt Instrument [Line Items]                              
Debt face amount                 550,000,000us-gaap_DebtInstrumentFaceAmount
/ us-gaap_DebtInstrumentAxis
= lmca_SiriusXm7ExchangeableSeniorSubordinatedNotesDue2014Member 		           
Debt Instrument, Convertible, Conversion Ratio                 543.1372us-gaap_DebtInstrumentConvertibleConversionRatio1
/ us-gaap_DebtInstrumentAxis
= lmca_SiriusXm7ExchangeableSeniorSubordinatedNotesDue2014Member 		           
Debt instrument, face amount per debenture                 1,000lmca_DebtInstrumentFaceAmountPerDebenture
/ us-gaap_DebtInstrumentAxis
= lmca_SiriusXm7ExchangeableSeniorSubordinatedNotesDue2014Member 		           
conversion price for exchangeable debt                 $ 1.841us-gaap_DebtInstrumentConvertibleConversionPrice1
/ us-gaap_DebtInstrumentAxis
= lmca_SiriusXm7ExchangeableSeniorSubordinatedNotesDue2014Member 		           
Debt Instrument, Basis Spread on Variable Rate   7.00%us-gaap_DebtInstrumentBasisSpreadOnVariableRate1
/ us-gaap_DebtInstrumentAxis
= lmca_SiriusXm7ExchangeableSeniorSubordinatedNotesDue2014Member 		                         
Debt Conversion, Converted Instrument, Amount   502,000,000us-gaap_DebtConversionConvertedInstrumentAmount1
/ us-gaap_DebtInstrumentAxis
= lmca_SiriusXm7ExchangeableSeniorSubordinatedNotesDue2014Member 		                         
Sirius XM 5.25% Senior Notes due 2022                              
Debt Instrument [Line Items]                              
Debt Instrument, Basis Spread on Variable Rate   5.25%us-gaap_DebtInstrumentBasisSpreadOnVariableRate1
/ us-gaap_DebtInstrumentAxis
= lmca_SiriusXm525SeniorNotesDue2022Member 		                         
Senior Notes, principal amount   400,000,000lmca_SeniorNotesPrincipalAmount
/ us-gaap_DebtInstrumentAxis
= lmca_SiriusXm525SeniorNotesDue2022Member 		                         
Sirius XM credit facility                              
Debt Instrument [Line Items]                              
Interest rate at year end   2.41%us-gaap_DebtInstrumentInterestRateEffectivePercentage
/ us-gaap_DebtInstrumentAxis
= lmca_SiriusXmCreditFacilityMember 		                         
Sirius XM Senior Notes due 2020 and 2023                              
Debt Instrument [Line Items]                              
Borrowings of debt                   989,000,000us-gaap_ProceedsFromIssuanceOfLongTermDebt
/ us-gaap_DebtInstrumentAxis
= lmca_SiriusXmSeniorNotesDue2020Ans2023Member 		         
Sirius XM Senior Notes due 2020 and 2023 | Revolving Credit Facility                              
Debt Instrument [Line Items]                              
Debt instrument, unused borrowing capacity, fee, percent   0.35%lmca_DebtInstrumentUnusedBorrowingCapacityFeePercent
/ us-gaap_DebtInstrumentAxis
= lmca_SiriusXmSeniorNotesDue2020Ans2023Member
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_RevolvingCreditFacilityMember 		                         
Sirius XM 4.25% Senior Notes due 2020                              
Debt Instrument [Line Items]                              
Debt Instrument, Interest Rate, Stated Percentage   4.25%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ us-gaap_DebtInstrumentAxis
= lmca_SiriusXM4.25SeniorNotesdue2020Member 		                         
Sirius XM 4.25% Senior Notes due 2020 | Senior Notes                              
Debt Instrument [Line Items]                              
Debt face amount   500,000,000us-gaap_DebtInstrumentFaceAmount
/ us-gaap_DebtInstrumentAxis
= lmca_SiriusXM4.25SeniorNotesdue2020Member
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_SeniorNotesMember 		                         
Sirius XM 4.625% Senior Notes due 2023                              
Debt Instrument [Line Items]                              
Debt face amount   500,000,000us-gaap_DebtInstrumentFaceAmount
/ us-gaap_DebtInstrumentAxis
= lmca_SiriusXM4.625SeniorNotesdue2023Member 		                         
Debt Instrument, Interest Rate, Stated Percentage   4.625%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ us-gaap_DebtInstrumentAxis
= lmca_SiriusXM4.625SeniorNotesdue2023Member 		                         
Debt Instrument, Basis Spread on Variable Rate   4.625%us-gaap_DebtInstrumentBasisSpreadOnVariableRate1
/ us-gaap_DebtInstrumentAxis
= lmca_SiriusXM4.625SeniorNotesdue2023Member 		                         
Sirius XM 5.75% Senior Notes due 2021                              
Debt Instrument [Line Items]                              
Debt face amount   600,000,000us-gaap_DebtInstrumentFaceAmount
/ us-gaap_DebtInstrumentAxis
= lmca_SiriusXM5.75SeniorNotesdue2021Member 		                         
Long-term Debt                         594,000,000us-gaap_LongTermDebt
/ us-gaap_DebtInstrumentAxis
= lmca_SiriusXM5.75SeniorNotesdue2021Member 		   
Debt Instrument, Interest Rate, Stated Percentage   5.75%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ us-gaap_DebtInstrumentAxis
= lmca_SiriusXM5.75SeniorNotesdue2021Member 		                         
Sirius XM 5.875% Senior Notes due 2020                              
Debt Instrument [Line Items]                              
Debt face amount   650,000,000us-gaap_DebtInstrumentFaceAmount
/ us-gaap_DebtInstrumentAxis
= lmca_SiriusXM5.875SeniorNotesdue2020Member 		                         
Long-term Debt                           643,000,000us-gaap_LongTermDebt
/ us-gaap_DebtInstrumentAxis
= lmca_SiriusXM5.875SeniorNotesdue2020Member 		 
Debt Instrument, Interest Rate, Stated Percentage   5.875%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ us-gaap_DebtInstrumentAxis
= lmca_SiriusXM5.875SeniorNotesdue2020Member 		                         
Sirius XM 6.00% Senior Notes Due 2024 [Member]                              
Debt Instrument [Line Items]                              
Debt face amount                             1,500,000,000us-gaap_DebtInstrumentFaceAmount
/ us-gaap_DebtInstrumentAxis
= lmca_SiriusXM6.00SeniorNotesDue2024Member
Debt discount                             17,000,000us-gaap_DebtInstrumentUnamortizedDiscount
/ us-gaap_DebtInstrumentAxis
= lmca_SiriusXM6.00SeniorNotesDue2024Member
Debt Instrument, Interest Rate, Stated Percentage   6.00%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ us-gaap_DebtInstrumentAxis
= lmca_SiriusXM6.00SeniorNotesDue2024Member 		                         
Common Class A                              
Debt Instrument [Line Items]                              
Investment Warrants, Exercise Price $ 255.64invest_InvestmentWarrantsExercisePrice
/ lmca_UnderlyingSharesAxis
= us-gaap_CommonClassAMember 		                           
Common Class A | 1.375% Cash Convertible Senior Notes due 2023                              
Debt Instrument [Line Items]                              
Debt Instrument, Convertible, Conversion Ratio                     5.5882us-gaap_DebtInstrumentConvertibleConversionRatio1
/ us-gaap_DebtInstrumentAxis
= lmca_A1.375CashConvertibleSeniorNotesdue2023Member
/ lmca_UnderlyingSharesAxis
= us-gaap_CommonClassAMember 		       
conversion price for exchangeable debt                     $ 178.95us-gaap_DebtInstrumentConvertibleConversionPrice1
/ us-gaap_DebtInstrumentAxis
= lmca_A1.375CashConvertibleSeniorNotesdue2023Member
/ lmca_UnderlyingSharesAxis
= us-gaap_CommonClassAMember 		       
SIRIUS XM | Sirius XM 7% Exchangeable Senior Subordinated Notes due 2014                              
Debt Instrument [Line Items]                              
Debt Conversion, Converted Instrument, Shares Issued   272,855,859us-gaap_DebtConversionConvertedInstrumentSharesIssued1
/ us-gaap_DebtInstrumentAxis
= lmca_SiriusXm7ExchangeableSeniorSubordinatedNotesDue2014Member
/ dei_LegalEntityAxis
= lmca_SiriusXmMember 		                         
1.375% Convertible Notes Bond Hedge Transaction                              
Debt Instrument [Line Items]                              
conversion price for exchangeable debt                     $ 178.95us-gaap_DebtInstrumentConvertibleConversionPrice1
/ us-gaap_OptionIndexedToIssuersEquityTypeAxis
= lmca_A1.375ConvertibleNotesBondHedgeTransactionMember 		       
Payments for Derivative Instrument, Financing Activities                     299,000,000us-gaap_PaymentsForDerivativeInstrumentFinancingActivities
/ us-gaap_OptionIndexedToIssuersEquityTypeAxis
= lmca_A1.375ConvertibleNotesBondHedgeTransactionMember 		       
1.375% Convertible Notes Bond Hedge Transaction | Common Class A                              
Debt Instrument [Line Items]                              
Forward contract, number of underlying shares                     5,588,200lmca_Forwardcontractnumberofunderlyingshares
/ us-gaap_OptionIndexedToIssuersEquityTypeAxis
= lmca_A1.375ConvertibleNotesBondHedgeTransactionMember
/ lmca_UnderlyingSharesAxis
= us-gaap_CommonClassAMember 		       
1.375% Convertible Notes Bond Hedge Transaction | Adjustments Due To Issuance Of Series C Common Stock and Liberty Broadband Spin Off [Member]                              
Debt Instrument [Line Items]                              
conversion price for exchangeable debt   $ 47.43us-gaap_DebtInstrumentConvertibleConversionPrice1
/ us-gaap_OptionIndexedToIssuersEquityTypeAxis
= lmca_A1.375ConvertibleNotesBondHedgeTransactionMember
/ us-gaap_StatementScenarioAxis
= lmca_AdjustmentsDueToIssuanceOfSeriesCCommonStockAndLibertyBroadbandSpinOffMember 		                         
1.375% Convertible Notes Bond Hedge Transaction | Adjustments Due To Issuance Of Series C Common Stock and Liberty Broadband Spin Off [Member] | Common Class A                              
Debt Instrument [Line Items]                              
Debt Instrument, Convertible, Conversion Ratio   21.0859us-gaap_DebtInstrumentConvertibleConversionRatio1
/ us-gaap_OptionIndexedToIssuersEquityTypeAxis
= lmca_A1.375ConvertibleNotesBondHedgeTransactionMember
/ us-gaap_StatementScenarioAxis
= lmca_AdjustmentsDueToIssuanceOfSeriesCCommonStockAndLibertyBroadbandSpinOffMember
/ lmca_UnderlyingSharesAxis
= us-gaap_CommonClassAMember 		                         
Debt instrument, face amount per debenture   $ 1,000lmca_DebtInstrumentFaceAmountPerDebenture
/ us-gaap_OptionIndexedToIssuersEquityTypeAxis
= lmca_A1.375ConvertibleNotesBondHedgeTransactionMember
/ us-gaap_StatementScenarioAxis
= lmca_AdjustmentsDueToIssuanceOfSeriesCCommonStockAndLibertyBroadbandSpinOffMember
/ lmca_UnderlyingSharesAxis
= us-gaap_CommonClassAMember 		                         
conversion price for exchangeable debt   $ 47.43us-gaap_DebtInstrumentConvertibleConversionPrice1
/ us-gaap_OptionIndexedToIssuersEquityTypeAxis
= lmca_A1.375ConvertibleNotesBondHedgeTransactionMember
/ us-gaap_StatementScenarioAxis
= lmca_AdjustmentsDueToIssuanceOfSeriesCCommonStockAndLibertyBroadbandSpinOffMember
/ lmca_UnderlyingSharesAxis
= us-gaap_CommonClassAMember 		                         
Forward contract, number of underlying shares   21,085,900lmca_Forwardcontractnumberofunderlyingshares
/ us-gaap_OptionIndexedToIssuersEquityTypeAxis
= lmca_A1.375ConvertibleNotesBondHedgeTransactionMember
/ us-gaap_StatementScenarioAxis
= lmca_AdjustmentsDueToIssuanceOfSeriesCCommonStockAndLibertyBroadbandSpinOffMember
/ lmca_UnderlyingSharesAxis
= us-gaap_CommonClassAMember 		                         
Common Class A | Adjustments Due To Issuance Of Series C Common Stock and Liberty Broadband Spin Off [Member]                              
Debt Instrument [Line Items]                              
Class of Warrant or Right, Exercise Price of Warrants or Rights   $ 64.46us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassAMember
/ us-gaap_StatementScenarioAxis
= lmca_AdjustmentsDueToIssuanceOfSeriesCCommonStockAndLibertyBroadbandSpinOffMember 		                         
Class of Warrant or Right, Outstanding   21,085,900us-gaap_ClassOfWarrantOrRightOutstanding
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassAMember
/ us-gaap_StatementScenarioAxis
= lmca_AdjustmentsDueToIssuanceOfSeriesCCommonStockAndLibertyBroadbandSpinOffMember 		                         
Class of Warrant or Right, Exercise Price of Warrants or Rights   $ 64.46us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassAMember
/ us-gaap_StatementScenarioAxis
= lmca_AdjustmentsDueToIssuanceOfSeriesCCommonStockAndLibertyBroadbandSpinOffMember