Allowance for Credit Losses (Reserve Allowance for Various Credit Loss) (Details) - USD ($) $ in Thousands |
9 Months Ended | 12 Months Ended |
|---|---|---|
Dec. 31, 2025 |
Mar. 31, 2025 |
|
| Valuation And Qualifying Accounts [Abstract] | ||
| March 31, 2022 | $ 8,634 | $ 8,105 |
| Transition adjustment current expected credit losses | 4,044 | 12,217 |
| Write-offs against allowance | 4,943 | 11,688 |
| December 31, 2023 | 7,735 | 8,634 |
| Trade Receivables | ||
| Valuation And Qualifying Accounts [Abstract] | ||
| March 31, 2022 | 5,082 | 6,236 |
| Transition adjustment current expected credit losses | 3,359 | 10,534 |
| Write-offs against allowance | 4,943 | 11,688 |
| December 31, 2023 | 3,498 | 5,082 |
| Investments, Fixed Maturities | ||
| Valuation And Qualifying Accounts [Abstract] | ||
| March 31, 2022 | 3,104 | 1,052 |
| Transition adjustment current expected credit losses | 685 | 2,052 |
| December 31, 2023 | 3,789 | 3,104 |
| Investments, Other | ||
| Valuation And Qualifying Accounts [Abstract] | ||
| March 31, 2022 | 448 | 817 |
| Transition adjustment current expected credit losses | 369 | |
| December 31, 2023 | $ 448 | $ 448 |