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Acquisitions Investments (Details) - Huatai Group [Member] - CHINA - USD ($) $ in Millions | 3 Months Ended | 12 Months Ended
--- | --- | ---
Mar. 31, 2021 | Dec. 31, 2019
Investment Holdings [Line Items] |  |
Equity Method Investment, Ownership Percentage | 47.10% |
Equity method investment, additional 7.1 percentage agreed on |  | 7.10%
Equity method investment, incremental 0.9 percent obtained | 0.90% |
Purchase of incremental ownership interest | $ 65 |

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