| Acquisitions and Restructurings - Pandora Acquisition Price Allocation (Details) - Sirius XM Holdings - Pandora - USD ($) $ in Millions | 3 Months Ended | 6 Months Ended | 
|---|---|---|
| Jun. 30, 2019 | Jun. 30, 2019 | |
| Acquisitions | ||
| Acquisition and other related costs | $ 7 | $ 83 | 
| Amounts of revenue since the acquisition date | 441 | 692 | 
| Net loss since the acquisition date | (56) | (178) | 
| Pro forma Revenue | 2,807 | 4,935 | 
| Pro forma Net earnings (loss) | 194 | 86 | 
| Pro forma Net earnings (loss) attributable to Liberty stockholders | $ 118 | $ (27) | 
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- Definition BusinessAcquisitionProFormaNetIncomeLossAttributableToCommonShareholders No definition available. 
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- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. No definition available. 
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- Definition The pro forma net Income or Loss for the period as if the business combination or combinations had been completed at the beginning of a period. Reference 1: http://www.xbrl.org/2003/role/disclosureRef 
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- Definition The pro forma revenue for a period as if the business combination or combinations had been completed at the beginning of the period. Reference 1: http://www.xbrl.org/2003/role/disclosureRef 
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- Definition This element represents acquisition-related costs incurred to effect a business combination which costs have been expensed during the period. Such costs include finder's fees; advisory, legal, accounting, valuation, and other professional or consulting fees; general administrative costs, including the costs of maintaining an internal acquisitions department; and may include costs of registering and issuing debt and equity securities. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef 
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- Definition This element represents the amount of earnings or loss of the acquiree since the acquisition date included in the consolidated income statement for the reporting period. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef 
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- Definition This element represents the amount of revenue of the acquiree since the acquisition date included in the consolidated income statement for the reporting period. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef 
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