| Benefit Plans - Sirius XM Holdings Inc. Deferred Compensation Plan (Narrative) (Details) - USD ($) $ in Millions | 3 Months Ended | 9 Months Ended | |||
|---|---|---|---|---|---|
| Sep. 30, 2025 | Sep. 30, 2024 | Sep. 30, 2025 | Sep. 30, 2024 | Dec. 31, 2024 | |
| Retirement Benefits [Abstract] | |||||
| Contributions to the DCP, net of withdrawals | $ (2) | $ (2) | $ (6) | $ (1) | |
| Fair value of investment assets related to deferred compensation plan | 60 | 60 | $ 60 | ||
| Gains (losses) on investments | $ 3 | $ 2 | $ 6 | $ 7 | |
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- Definition Deferred Compensation Arrangement with Individual, Contributions by Employer, Net Of Withdrawals No definition available. 
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- Definition Deferred Compensation Arrangement with Individual, Gain (Loss) on Investment No definition available. 
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- References No definition available. 
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- Definition Carrying amount as of the balance sheet date of assets held under deferred compensation agreements. Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef 
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