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Fair Value Measurements - Narrative (Details) $ in Millions | 3 Months Ended
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Mar. 31, 2022 USD ($) professional
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |
AFG's internal investment professionals | professional | 20
Percentage of level three assets that were priced using a discounted cash flow approach | 61.00%
Level three assets that were priced using a discounted cash flow approach | $ 361
Percentage of level three assets, equity securities, priced using broker quotes and internal models | 28.00%
Level three assets, equity securities, priced using broker quotes and internal models | $ 168
Contingent consideration — acquisitions |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |
Change in fair value of contingent consideration liability | $ 0
Level 3 | Continuing operations |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |
Level 3 assets as a percentage of total assets measured at fair value | 6.00%
Percentage of level 3 assets that were priced using non-binding broker quotes | 16.00%
Level 3 assets that were priced using non-binding broker quotes | $ 164
Level 3 assets that were priced by pricing services. | $ 58
Percentage of level 3 assets that were priced by pricing services | 6.00%
Percentage of level 3 equity investments that do not qualify for equity accounting | 19.00%
Level 3 assets that are equity securities that do not qualify for equity accounting | $ 186
Internally developed level 3 assets | $ 590
Percentage of internally developed level 3 assets compared to total level 3 assets | 59.00%

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