Business & Basis of Presentation (Details 1) (Common Stock [Member], Liberty Media [Member])	Dec. 31, 2014
Common Stock [Member] \| Liberty Media [Member]
Related Party Transaction [Line Items]
Related party ownership percentage (greater than 50%)	50.00%

Related Party Transaction, Related Party Ownership Percentage

No definition available.

Name:	siri_RelatedPartyTransactionRelatedPartyOwnershipPercentage
Namespace Prefix:	siri_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant