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Fair value measurements (Narrative) (Details) - USD ($) $ in Millions | 3 Months Ended | 9 Months Ended
--- | --- | ---
Sep. 30, 2022 | Sep. 30, 2021 | Sep. 30, 2022 | Sep. 30, 2021
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items] |  |  |  |
Net realized gains (losses) | $ (384) | $ (21) | $ (787) | $ 833
GLB | Variable Annuity |  |  |  |
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items] |  |  |  |
Realized Gains Losses As A Result of Valuation Model Refinement | $ (40) |  |  |

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- Definition Amount of realized gain (loss) on investment. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 220 -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-04.3(a)) -URI https://asc.fasb.org/extlink&oid=120400993&loc=SL114874131-224263 + Details
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