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Income Taxes - Schedule of Expiration Periods of Deferred Tax Assets (Details) - USD ($) $ in Millions | Dec. 31, 2019 | Dec. 31, 2018 | Dec. 31, 2017 | Dec. 31, 2016
--- | --- | --- | --- | ---
Tax Credit Carryforward [Line Items] |  |  |  |
Tax loss carryforwards | $ 2,932 |  |  |
Tax credit carryforwards | 379 |  |  |
Other | 1,208 |  |  |
Valuation allowance | (2,256) | $ (2,486) | $ (2,584) | $ (1,940)
Deferred tax assets, net | 2,263 | $ 2,336 |  |
Expires within 10 years |  |  |  |
Tax Credit Carryforward [Line Items] |  |  |  |
Tax loss carryforwards | 452 |  |  |
Tax credit carryforwards | 300 |  |  |
Other | 0 |  |  |
Valuation allowance | (711) |  |  |
Deferred tax assets, net | 41 |  |  |
Expires within 11-20 years |  |  |  |
Tax Credit Carryforward [Line Items] |  |  |  |
Tax loss carryforwards | 235 |  |  |
Tax credit carryforwards | 69 |  |  |
Other | 0 |  |  |
Valuation allowance | (176) |  |  |
Deferred tax assets, net | 128 |  |  |
No expiration |  |  |  |
Tax Credit Carryforward [Line Items] |  |  |  |
Tax loss carryforwards | 2,245 |  |  |
Tax credit carryforwards | 10 |  |  |
Other | 120 |  |  |
Valuation allowance | (1,306) |  |  |
Deferred tax assets, net | 1,069 |  |  |
Other(2) |  |  |  |
Tax Credit Carryforward [Line Items] |  |  |  |
Tax loss carryforwards | 0 |  |  |
Tax credit carryforwards | 0 |  |  |
Other | 1,088 |  |  |
Valuation allowance | (63) |  |  |
Deferred tax assets, net | $ 1,025 |  |  |

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