Benefits Plans.

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Employees contribution of their pretax earnings to subsidiary plan maximum.

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Employees contribution of their pretax earnings to subsidiary plan minimum.

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Employee voluntary contributions to be matched in the form of common shares.

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Percentage of weighting to observable historical volatility for company's common stock.

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Vesting percentage of Employer contributions for each year of employment.

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Weighted average expected period for recognition of compensation expenses.

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Represents the expense recognized during the period arising from equity-based compensation arrangements (for example, shares of stock, unit, stock options or other equity instruments) with employees, directors and certain consultants qualifying for treatment as employees.

+ References

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As of the balance sheet date, the aggregate unrecognized cost of equity-based awards made to employees under equity-based compensation awards that have yet to vest.

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The intrinsic value of equity-based payment equity instruments, excluding stock (or unit) options, that vested during the reporting period as calculated by applying the disclosed pricing methodology.

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The difference between the maximum number of shares (or other type of equity) authorized for issuance under the plan (including the effects of amendments and adjustments), and the sum of: 1) the number of shares (or other type of equity) already issued upon exercise of options or other equity-based awards under the plan; and 2) shares (or other type of equity) reserved for issuance on granting of outstanding awards, net of cancellations and forfeitures, if applicable.

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The total accumulated difference between fair values of underlying shares on dates of exercise and exercise price on options which were exercised (or share units converted) into shares during the reporting period under the plan.

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- Definition

Net number of share options (or share units) granted during the period.

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- Definition

The weighted average grant-date fair value of options granted during the reporting period as calculated by applying the disclosed option pricing methodology.

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Benefits Plans (Details Textual) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2011	Sep. 30, 2010	Dec. 31, 2010
Benefits Plans (Textual) [Abstract]
Share-based compensation expense	$ 13,983	$ 16,220	$ 36,006	$ 47,443
Percentage of weighting of observable historical volatility in 2010					100.00%
Employee Stock Option [Member]
Benefits Plans (Textual) [Abstract]
Share-based compensation expense	13,201	11,679	33,098	32,459
Weighted average grant date fair value of options granted			$ 1.04	$ 0.66
Granted, options			77,451,000
Total Intrinsic value of stock options exercised			10,011	5,611
Sirius XM Savings Plan [Member]
Benefits Plans (Textual) [Abstract]
Share-based compensation expense	782	724	2,365	2,649
Percentage limit of an employee's pre-tax salary the Company will match in the form of shares of common stock	50% of employees voluntary contributions, up to 6%		50% of employees voluntary contributions, up to 6%
Limit of employee contributions of pre-tax eligible earnings to Company 401(k) Savings Plan	50.00%		50.00%
Minimum of employee contributions of pre-tax eligible earnings to Company 401(k) Savings Plan	1.00%		1.00%
Vesting percentage of Employer contributions for each year of employment	33.33%		33.33%
Stock Compensation Plan [Member]
Benefits Plans (Textual) [Abstract]
Common stock available for future grants	196,121,000		196,121,000
Restricted Stock and Restricted Stock Units RSU [Member]
Benefits Plans (Textual) [Abstract]
Share-based compensation expense	0	1,385	543	6,059
Total intrinsic value of restricted stock and restricted stock units that vested			$ 3,178,000	$ 3,923,000
Restricted Stock Units RSU and Stock Options [Member]
Benefits Plans (Textual) [Abstract]
Total unrecognized compensation costs related to unvested share based payment awards for restricted stock units, net of estimated forfeitures	145,460		145,460		108,170
Weighted average expected period for recognition of compensation expenses	3 years		3 years
Profit Sharing [Member]
Benefits Plans (Textual) [Abstract]
Share-based compensation expense	$ 0	$ 2,432	$ 0	$ 6,276
Third Parties [Member]
Benefits Plans (Textual) [Abstract]
Granted, options	0	0	0	0