Investments - Schedule of Short-term, Long-term Investments and Marketable Securities (Details) - USD ($) $ in Thousands |
Dec. 31, 2024 |
Sep. 30, 2024 |
|---|---|---|
| Schedule Of Held To Maturity Securities And Marketable Securities [Line Items] | ||
| Current investments, Available-for-sale, Adjusted Basis | $ 498,743 | $ 577,465 |
| Current investments, Available-for-sale, Gross Unrealized Gains | 387 | 837 |
| Current investments, Available-for-sale, Gross Unrealized Losses | (84) | (26) |
| Current investments, Available-for-sale, Fair Value | 499,046 | 578,276 |
| Available-for-sale securities | ||
| Schedule Of Held To Maturity Securities And Marketable Securities [Line Items] | ||
| Current investments, Available-for-sale, Adjusted Basis | 498,743 | 577,465 |
| Current investments, Available-for-sale, Gross Unrealized Gains | 387 | 837 |
| Current investments, Available-for-sale, Gross Unrealized Losses | (84) | (26) |
| Current investments, Available-for-sale, Fair Value | $ 499,046 | $ 578,276 |