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Acquisitions Acquisitions (narrative) (Details) - USD ($) $ in Millions | 1 Months Ended | 9 Months Ended
--- | --- | ---
Jan. 31, 2020 | Sep. 30, 2020 | Sep. 30, 2019
Business Acquisition [Line Items] |  |  |
Payments for Other Deposits |  | $ 503 |
CHINA | Huatai Group [Member] |  |  |
Business Acquisition [Line Items] |  |  |
Payments for Other Deposits | $ 1,550 | $ 503 | $ 0
Equity method investment, additional 15.3 ownership percentage obtained |  | 15.30% |
Equity Method Investments |  | $ 2,400 |

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