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Acquisitions and Sale of Businesses - Narrative on sale of businesses (Details) - USD ($) $ in Millions | 12 Months Ended |
--- | --- | ---
Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018 | Jun. 30, 2020
Sale of Businesses |  |  |  |
Proceeds from sale of businesses | $ 3 | $ 0 | $ 0 |
Income tax expense (benefit) | 127 | $ 239 | $ 122 |
Neon Capital Limited |  |  |  |
Sale of Businesses |  |  |  |
Proceeds from sale of businesses | $ 6 |  |  |
Carrying value of assets and liabilities disposed, percentage of total assets and liabilities | 1.00% |  |  |
Income tax expense (benefit) | $ (72) |  |  |
Neon Capital Limited Executives | Neon Capital Limited |  |  |  |
Sale of Businesses |  |  |  |
Percent of noncontrolling interest acquired from former and current Neon executives |  |  |  | 100.00%

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