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Income Taxes (Narrative) (Details) - USD ($) $ in Millions | 12 Months Ended
--- | ---
Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018
Income Tax Contingency [Line Items] |  |  |
Unrecognized Tax Benefits, Income Tax Penalties and Interest Expense | $ 52 | $ 19 | $ 6
Unrecognized Tax Benefits, Income Tax Penalties and Interest Accrued | 128 | $ 76 |
Significant Change in Unrecognized Tax Benefits is Reasonably Possible, Amount of Unrecorded Benefit | 39 |  |
Unrecognized Tax Benefits that Would Impact Effective Tax Rate | $ 1,000 |  |
Federal [Member] | Earliest Tax Year [Member] |  |  |
Income Tax Contingency [Line Items] |  |  |
Tax Credit Carryforward, Expiration Date | Jan. 01, 2023 |  |
Open Tax Year | 2017 |  |
Federal [Member] | Latest Tax Year [Member] |  |  |
Income Tax Contingency [Line Items] |  |  |
Tax Credit Carryforward, Expiration Date | Dec. 31, 2037 |  |
Open Tax Year | 2020 |  |
State [Member] | Earliest Tax Year [Member] |  |  |
Income Tax Contingency [Line Items] |  |  |
Tax Credit Carryforward, Expiration Date | Jan. 01, 2021 |  |
Open Tax Year | 2013 |  |
State [Member] | Latest Tax Year [Member] |  |  |
Income Tax Contingency [Line Items] |  |  |
Tax Credit Carryforward, Expiration Date | Dec. 31, 2040 |  |
Open Tax Year | 2020 |  |
Non-U.S [Member] | Earliest Tax Year [Member] |  |  |
Income Tax Contingency [Line Items] |  |  |
Open Tax Year | 2015 |  |
Non-U.S [Member] | Latest Tax Year [Member] |  |  |
Income Tax Contingency [Line Items] |  |  |
Open Tax Year | 2020 |  |
Finite-lived NOL carryforwards [Member] | Federal [Member] |  |  |
Income Tax Contingency [Line Items] |  |  |
Operating Loss Carryforwards | $ 100 |  |
Indefinite NOL carryforwards [Member] | Federal [Member] |  |  |
Income Tax Contingency [Line Items] |  |  |
Operating Loss Carryforwards | $ 309 |  |

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