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Business and Basis of Presentation (Details) $ in Millions | 3 Months Ended |
--- | --- | ---
Mar. 31, 2021 USD ($) | Mar. 31, 2022 Company
Debt Securities, Available-for-sale, Unrealized Loss Position [Line Items] |  |
Number of holding companies with outstanding public debt | Company |  | 2
Municipal Assurance Corp |  |
Debt Securities, Available-for-sale, Unrealized Loss Position [Line Items] |  |
Write off of licenses | $ | $ 16 |

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