Business (Details Textual)	3 Months Ended
	Mar. 31, 2012 Line
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of satellite radio systems (in line)	2
Minimum [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Length of prepaid subscriptions, term (in years)	3 months
Maximum [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Length of prepaid subscriptions, term (in years)	12 months