Sirius XM Holdings Inc. Annual report pursuant to Section 13 and 15(d)

Composition of Certain Financial Statement Captions - Schedule of cash, cash equivalents and investments (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Cash, Cash Equivalents and Investments
Total cash and cash equivalents	$ 175,957	$ 245,755
Total short-term investments	178,631us-gaap_ShortTermInvestments	98,662us-gaap_ShortTermInvestments
Total long-term investments	104,243us-gaap_LongTermInvestments	105,686us-gaap_LongTermInvestments
Total cash, cash equivalents and investments	458,831p_CashCashEquivalentsAndInvestments	450,103p_CashCashEquivalentsAndInvestments
Cash
Cash, Cash Equivalents and Investments
Total cash and cash equivalents	72,487	89,176
Money market funds
Cash, Cash Equivalents and Investments
Total cash and cash equivalents	89,113	98,437
Commercial paper
Cash, Cash Equivalents and Investments
Total cash and cash equivalents	9,349	54,247
Total short-term investments	45,443	47,526
Corporate debt securities
Cash, Cash Equivalents and Investments
Total cash and cash equivalents	5,008	3,895
Total short-term investments	128,691	50,436
Total long-term investments	100,998	100,690
U.S. government and government agency debt securities
Cash, Cash Equivalents and Investments
Total short-term investments	4,497	700
Total long-term investments	$ 3,245	$ 4,996