Fair Value Measurements (Narratives) (Details) - USD ($) $ in Thousands |
Sep. 30, 2025 |
Mar. 31, 2025 |
|---|---|---|
| Financial Instruments Financial Assets Balance Sheet Groupings [Abstract] | ||
| Cash and Cash Equivalent | $ 1,082,820 | $ 988,828 |
| Financial Instruments Financial Liabilities Balance Sheet Groupings [Abstract] | ||
| Liabilities Fair Value Carrying Value | 9,662,415 | 9,140,047 |
| Level 3 [Member] | ||
| Financial Instruments Financial Liabilities Balance Sheet Groupings [Abstract] | ||
| Liabilities Fair Value Carrying Value | 2,461,369 | 2,436,537 |
| Carrying Value [Member] | ||
| Financial Instruments Financial Assets Balance Sheet Groupings [Abstract] | ||
| Cash and Cash Equivalent | 786,700 | 700,000 |
| Financial Instruments Financial Liabilities Balance Sheet Groupings [Abstract] | ||
| Liabilities Fair Value Carrying Value | $ 10,242,515 | $ 9,732,070 |