Quarterly report pursuant to Section 13 or 15(d)

Basis of Presentation (Details)

v2.4.1.9
Basis of Presentation (Details) (USD $)
In Millions, except Share data, unless otherwise specified
1 Months Ended 3 Months Ended 0 Months Ended 3 Months Ended
Oct. 31, 2014
Mar. 31, 2015
Jul. 23, 2014
Mar. 31, 2014
Entity Information [Line Items]        
Additional paid in capital deficit reclassification   $ 64lmca_AdjustmentToAdditionalPaidInCapitalDeficitReclassification    
Cash received from consolidated subsidiary 300lmca_CashReceivedFromConsolidatedSubsidiary      
Common Class A        
Entity Information [Line Items]        
Number of shares issued during the period for each share of Series A and Series B stock held by shareholders prior to the distribution     2lmca_NumberofsharesissuedduringtheperiodforeachshareofSeriesAandSeriesBstockheldbyshareholderspriortothedistribution
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassAMember
 
Common Class C        
Entity Information [Line Items]        
Number of shares issued during the period for each share of Series A and Series B stock held by shareholders prior to the distribution     2lmca_NumberofsharesissuedduringtheperiodforeachshareofSeriesAandSeriesBstockheldbyshareholderspriortothedistribution
/ us-gaap_StatementClassOfStockAxis
= us-gaap_CommonClassCMember
 
Liberty Broadband        
Entity Information [Line Items]        
Common Stock, Shares Subscribed but Unissued   1us-gaap_CommonStockSharesSubscribedButUnissued
/ dei_LegalEntityAxis
= lmca_LibertyBroadbandMember
   
Number of shares received in spin-off   0.25lmca_Numberofsharesreceivedinspinoff
/ dei_LegalEntityAxis
= lmca_LibertyBroadbandMember
   
Liberty Interactive Corporation Starz Tripco Liberty Broadband [Member]        
Entity Information [Line Items]        
Related Party Transaction, Amounts of Transaction   3us-gaap_RelatedPartyTransactionAmountsOfTransaction
/ dei_LegalEntityAxis
= lmca_LibertyInteractiveCorporationStarzTripcoLibertyBroadbandMember
  2us-gaap_RelatedPartyTransactionAmountsOfTransaction
/ dei_LegalEntityAxis
= lmca_LibertyInteractiveCorporationStarzTripcoLibertyBroadbandMember
Starz, LLC | Lease Agreements        
Entity Information [Line Items]        
Related Party Transaction, Amounts of Transaction   $ 3us-gaap_RelatedPartyTransactionAmountsOfTransaction
/ dei_LegalEntityAxis
= lmca_StarzLlcMember
/ us-gaap_TypeOfArrangementAxis
= us-gaap_LeaseAgreementsMember