Income Taxes (Narrative) (Details) - USD ($) $ in Millions  | 
3 Months Ended | 9 Months Ended | |||
|---|---|---|---|---|---|
Sep. 30, 2019  | 
Sep. 30, 2018  | 
Sep. 30, 2019  | 
Sep. 30, 2018  | 
Dec. 31, 2018  | 
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| Income Tax Contingency [Line Items] | |||||
| Income tax expense | $ (79) | $ (71) | $ (238) | $ (229) | |
| Effective Income Tax Rate Reconciliation, Percent | 29.60% | 28.20% | 28.70% | 26.40% | |
| UNITED STATES | |||||
| Income Tax Contingency [Line Items] | |||||
| Effective income tax rate reconciliation, at federal statutory income tax rate, percent | 21.00% | ||||
| Liberty | Tax Agreement | |||||
| Income Tax Contingency [Line Items] | |||||
| Current tax payments due to related parties | $ 5 | $ 5 | $ 26 | ||
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- Definition Amount of payable due to an entity that is affiliated with the reporting entity by means of direct or indirect ownership. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef 
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- Definition Percentage of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef 
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- Definition Percentage of domestic federal statutory tax rate applicable to pretax income (loss). Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef 
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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 Amount of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations. Reference 1: http://www.xbrl.org/2003/role/disclosureRef 
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