v3.26.1
Investments - Schedule of Investments (Details) - USD ($)
$ in Thousands
Jun. 30, 2026
Sep. 30, 2025
Debt Securities, Available-for-Sale [Line Items]    
Available-for-sale securities, Adjusted Basis $ 1,553,308 $ 689,882
Available-for-sale securities, Gross Unrealized Gains 433 2,956
Available-for-sale securities, Gross Unrealized Losses (6,540) (20)
Available-for-sale securities, Fair Value 1,547,201 692,818
Available-for-sale securities    
Debt Securities, Available-for-Sale [Line Items]    
Available-for-sale securities, Adjusted Basis 1,553,308 689,882
Available-for-sale securities, Gross Unrealized Gains 433 2,956
Available-for-sale securities, Gross Unrealized Losses (6,540) (20)
Available-for-sale securities, Fair Value $ 1,547,201 $ 692,818