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v3.25.1

Investments (Narratives) (Details) - USD ($) $ in Millions | 12 Months Ended
--- | ---
Mar. 31, 2025 | Mar. 31, 2024 | Mar. 31, 2023
Debt Securities, Available-for-Sale [Line Items] |  |  |
Available for sale securities, realized gain | $ 439.4 | $ 667.0 | $ 196.2
Fair value of sold available-for-sale securities | 13.3 | 106.5 |
Provision for (or reversal of) credit losses | 2.1 | 1.0 |
Assets held by insurance regulators | 21.5 | $ 23.1 |
Self-storage facilities and commercial properties | Mortgages [Member] |  |  |
Debt Securities, Available-for-Sale [Line Items] |  |  |
Provision for (or reversal of) credit losses | $ 0.4 |  |
Self-storage facilities and commercial properties | Mortgages [Member] | Minimum [Member] |  |  |
Debt Securities, Available-for-Sale [Line Items] |  |  |
Mortgage loan interest rate | 3.50% |  |
Self-storage facilities and commercial properties | Mortgages [Member] | Maximum [Member] |  |  |
Debt Securities, Available-for-Sale [Line Items] |  |  |
Mortgage loan interest rate | 7.70% |  |

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