| Income Taxes (Details) - USD ($) $ in Millions | 12 Months Ended | ||
|---|---|---|---|
| Dec. 31, 2018 | Dec. 31, 2017 | Dec. 31, 2016 | |
| Income Tax Expense (Benefit) [Abstract] | |||
| Federal | $ (14) | $ 38 | $ (39) | 
| State and local | 13 | (30) | (29) | 
| Foreign | (8) | (9) | |
| Current Income Tax Expense (Benefit) | (9) | (1) | (68) | 
| Federal | (228) | 578 | (388) | 
| State and local | (2) | (21) | (39) | 
| Foreign | 63 | 507 | |
| Deferred Income Tax Expense (Benefit), Total | (167) | 1,064 | (427) | 
| Income tax benefit (expense) | $ (176) | $ 1,063 | $ (495) | 
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- References No definition available. 
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- Definition Amount of current federal tax expense (benefit) pertaining to income (loss) from continuing operations. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef 
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- Definition Amount of current foreign income tax expense (benefit) pertaining to income (loss) from continuing operations. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef 
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- Definition Amount of current income tax expense (benefit) pertaining to taxable income (loss) from continuing operations. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef 
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- Definition Amount of current state and local tax expense (benefit) pertaining to income (loss) from continuing operations. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef 
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- Definition Amount of deferred federal income tax expense (benefit) pertaining to income (loss) from continuing operations. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef 
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- Definition Amount of deferred foreign income tax expense (benefit) pertaining to income (loss) from continuing operations. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef 
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| X | ||||||||||
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- Definition Amount of deferred income tax expense (benefit) pertaining to income (loss) from continuing operations. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef 
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| X | ||||||||||
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- Definition Amount of deferred state and local tax expense (benefit) pertaining to income (loss) from continuing operations. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef 
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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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