Summary of Significant Accounting Policies - Summary of Assets and Liabilities Measured at Fair Value (Details) - USD ($) $ in Thousands		Sep. 30, 2015	Dec. 31, 2014
Liabilities:
Debt, fair value	[1]	$ 5,419,038	$ 4,613,044
Level 1 [Member]
Liabilities:
Debt, fair value	[1]	0	0
Level 2 [Member]
Liabilities:
Debt, fair value	[1]	5,419,038	4,613,044
Level 3 [Member]
Liabilities:
Debt, fair value	[1]	0	0
Sirius XM Canada [Member]
Assets:
Investment, fair value	[2]	173,900	246,500
Sirius XM Canada [Member] | Level 1 [Member]
Assets:
Investment, fair value	[2]	173,900	246,500
Sirius XM Canada [Member] | Level 2 [Member]
Assets:
Investment, fair value	[2]	0	0
Sirius XM Canada [Member] | Level 3 [Member]
Assets:
Investment, fair value	[2]	$ 0	$ 0

[1] The fair value for non-publicly traded instruments is based upon estimates from a market maker and brokerage firm. Refer to Note 11 for information related to the carrying value of our debt as of September 30, 2015 and December 31, 2014.

[2] This amount approximates fair value. The carrying value of our investment in Sirius XM Canada was $0 and $2,654 as of September 30, 2015 and December 31, 2014, respectively.