Quarterly report pursuant to Section 13 or 15(d)

Debt (Details 3)

v2.4.1.9
Debt (Details 3) (USD $)
 3 Months Ended 0 Months Ended 1 Months Ended 0 Months Ended
Mar. 31, 2015
Mar. 31, 2014
Apr. 30, 2013
Oct. 31, 2014
Dec. 31, 2014
Oct. 17, 2013
Dec. 31, 2012
Debt Instrument [Line Items]              
Long-term Debt $ 6,471,000,000us-gaap_LongTermDebt       $ 5,852,000,000us-gaap_LongTermDebt    
Borrowings of debt 1,275,000,000us-gaap_ProceedsFromIssuanceOfLongTermDebt            
Repayments of Long-term Debt 658,000,000us-gaap_RepaymentsOfLongTermDebt 821,000,000us-gaap_RepaymentsOfLongTermDebt          
Sirius XM credit facility              
Debt Instrument [Line Items]              
Long-term Debt         380,000,000us-gaap_LongTermDebt
/ us-gaap_LongtermDebtTypeAxis
= lmca_SiriusXmCreditFacilityMember 		   
Debt instrument, unused borrowing capacity, fee, percent 0.30%lmca_DebtInstrumentUnusedBorrowingCapacityFeePercent
/ us-gaap_LongtermDebtTypeAxis
= lmca_SiriusXmCreditFacilityMember 		           
Line of Credit Facility, Remaining Borrowing Capacity 1,250,000,000us-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 98.00%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 130.00%us-gaap_DebtInstrumentConvertibleThresholdPercentageOfStockPriceTrigger
/ us-gaap_DebtInstrumentAxis
= lmca_A1.375CashConvertibleSeniorNotesdue2023Member 		           
$1 billion margin loan due 2014              
Debt Instrument [Line Items]              
Interest rate at year end 2.03%us-gaap_DebtInstrumentInterestRateEffectivePercentage
/ us-gaap_DebtInstrumentAxis
= lmca_A1billionmarginloandue2014Member 		           
$1 billion margin loan due 2014 | Term loan              
Debt Instrument [Line Items]              
Debt face amount       250,000,000us-gaap_DebtInstrumentFaceAmount
/ us-gaap_DebtInstrumentAxis
= lmca_A1billionmarginloandue2014Member
/ us-gaap_LongtermDebtTypeAxis
= lmca_TermloanMember 		     
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]              
Debt face amount       750,000,000us-gaap_DebtInstrumentFaceAmount
/ us-gaap_DebtInstrumentAxis
= lmca_A1billionmarginloandue2014Member
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_RevolvingCreditFacilityMember 		     
Borrowings of debt     450,000,000us-gaap_ProceedsFromIssuanceOfLongTermDebt
/ us-gaap_DebtInstrumentAxis
= lmca_A1billionmarginloandue2014Member
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_RevolvingCreditFacilityMember 		       
Debt Instrument, Description of Variable Rate Basis       LIBOR      
Debt instrument, basis spread on variable rate, floor       1.75%lmca_DebtInstrumentBasisSpreadOnVariableRateFloor
/ us-gaap_DebtInstrumentAxis
= lmca_A1billionmarginloandue2014Member
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_RevolvingCreditFacilityMember 		     
Debt instrument, basis spread on variable rate, cap       2.50%lmca_DebtInstrumentBasisSpreadOnVariableRateCap
/ us-gaap_DebtInstrumentAxis
= lmca_A1billionmarginloandue2014Member
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_RevolvingCreditFacilityMember 		     
Debt instrument, unused borrowing capacity, fee, percent       0.75%lmca_DebtInstrumentUnusedBorrowingCapacityFeePercent
/ us-gaap_DebtInstrumentAxis
= lmca_A1billionmarginloandue2014Member
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_RevolvingCreditFacilityMember 		     
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 		           
Sirius Xm 5.375 Senior Notes Due 2025              
Debt Instrument [Line Items]              
Debt face amount 1,000,000,000us-gaap_DebtInstrumentFaceAmount
/ us-gaap_DebtInstrumentAxis
= lmca_SiriusXm5.375SeniorNotesDue2025Member 		           
Debt discount 11,000,000us-gaap_DebtInstrumentUnamortizedDiscount
/ us-gaap_DebtInstrumentAxis
= lmca_SiriusXm5.375SeniorNotesDue2025Member 		           
Debt Instrument, Interest Rate, Stated Percentage 5.375%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ us-gaap_DebtInstrumentAxis
= lmca_SiriusXm5.375SeniorNotesDue2025Member 		           
Common Class A | 1.375% Cash Convertible Senior Notes due 2023              
Debt Instrument [Line Items]              
Debt Instrument, Convertible, Conversion Ratio         21.0859us-gaap_DebtInstrumentConvertibleConversionRatio1
/ us-gaap_DebtInstrumentAxis
= lmca_A1.375CashConvertibleSeniorNotesdue2023Member
/ lmca_UnderlyingSharesAxis
= us-gaap_CommonClassAMember 		5.5882us-gaap_DebtInstrumentConvertibleConversionRatio1
/ us-gaap_DebtInstrumentAxis
= lmca_A1.375CashConvertibleSeniorNotesdue2023Member
/ lmca_UnderlyingSharesAxis
= us-gaap_CommonClassAMember 		 
conversion price for exchangeable debt         $ 47.43us-gaap_DebtInstrumentConvertibleConversionPrice1
/ us-gaap_DebtInstrumentAxis
= lmca_A1.375CashConvertibleSeniorNotesdue2023Member
/ lmca_UnderlyingSharesAxis
= us-gaap_CommonClassAMember 		$ 178.95us-gaap_DebtInstrumentConvertibleConversionPrice1
/ us-gaap_DebtInstrumentAxis
= lmca_A1.375CashConvertibleSeniorNotesdue2023Member
/ lmca_UnderlyingSharesAxis
= us-gaap_CommonClassAMember 		 
1.375% Convertible Notes Bond Hedge Transaction              
Debt Instrument [Line Items]              
Forward contract, number of underlying shares         21,085,900lmca_Forwardcontractnumberofunderlyingshares
/ us-gaap_OptionIndexedToIssuersEquityTypeAxis
= lmca_A1.375ConvertibleNotesBondHedgeTransactionMember 		   
Derivative, Cap Price         47.43us-gaap_DerivativeCapPrice
/ us-gaap_OptionIndexedToIssuersEquityTypeAxis
= lmca_A1.375ConvertibleNotesBondHedgeTransactionMember 		178.95us-gaap_DerivativeCapPrice
/ us-gaap_OptionIndexedToIssuersEquityTypeAxis
= lmca_A1.375ConvertibleNotesBondHedgeTransactionMember 		 
Payments for Derivative Instrument, Investing Activities           $ 299,000,000us-gaap_PaymentsForDerivativeInstrumentInvestingActivities
/ 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