Quarterly report pursuant to Section 13 or 15(d)

Summary of Significant Accounting Policies - Summary of Assets and Liabilities Measured at Fair Value (Parenthetical) (Details)

v2.4.1.9
Summary of Significant Accounting Policies - Summary of Assets and Liabilities Measured at Fair Value (Parenthetical) (Details) (Sirius XM Canada [Member], USD $)
In Thousands, unless otherwise specified
Mar. 31, 2015
Dec. 31, 2014
Sirius XM Canada [Member]
   
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]    
Investment balance, carrying value $ 0us-gaap_EquityMethodInvestments
/ us-gaap_RelatedPartyTransactionsByRelatedPartyAxis
= siri_SiriusXmCanadaMember
$ 2,654us-gaap_EquityMethodInvestments
/ us-gaap_RelatedPartyTransactionsByRelatedPartyAxis
= siri_SiriusXmCanadaMember