Investments (Narratives) (Details) - USD ($) $ in Millions |
3 Months Ended | 6 Months Ended | |||
|---|---|---|---|---|---|
Sep. 30, 2025 |
Sep. 30, 2024 |
Sep. 30, 2025 |
Sep. 30, 2024 |
Mar. 31, 2025 |
|
| Statutory Accounting Practices, Statutory Amount Available for Dividend Payments [Abstract] | |||||
| Assets Held by Insurance Regulators | $ 21.0 | $ 21.0 | $ 21.5 | ||
| Available-for-sale Securities [Abstract] | |||||
| Available for sale securities, realized gains | $ 2.4 | $ 14.0 | |||
| Provision for Loan, Lease, and Other Losses [Abstract] | |||||
| Financing Receivable, Credit Loss, Expense (Reversal) | $ 1.5 | $ 1.8 | |||