v3.26.1
Fair Value Measurements (Details) - USD ($)
$ in Thousands
Jun. 30, 2026
Sep. 30, 2025
Jun. 30, 2025
Carrying Value      
Financial assets:      
Promissory note receivable from Founders   $ 24,369 $ 17,525
Investments in unconsolidated affiliates $ 26,549 18,123 13,753
Carrying Value | 2029 Convertible Notes      
Financial liabilities:      
Debt instruments, fair value 226,021 225,258 224,982
Carrying Value | 2032 Senior Notes      
Financial liabilities:      
Debt instruments, fair value 293,473 292,818 292,619
Estimated Fair Value      
Financial assets:      
Promissory note receivable from Founders   24,369 17,525
Investments in unconsolidated affiliates 65,681 59,729 50,657
Estimated Fair Value | 2029 Convertible Notes      
Financial liabilities:      
Debt instruments, fair value 708,400 422,931 330,050
Estimated Fair Value | 2032 Senior Notes      
Financial liabilities:      
Debt instruments, fair value 315,000 320,734 316,406
Estimated Fair Value | Level 1      
Financial assets:      
Promissory note receivable from Founders   0 0
Investments in unconsolidated affiliates 64,083 58,573 49,807
Estimated Fair Value | Level 1 | 2029 Convertible Notes      
Financial liabilities:      
Debt instruments, fair value 0 0 0
Estimated Fair Value | Level 1 | 2032 Senior Notes      
Financial liabilities:      
Debt instruments, fair value 0 0 0
Estimated Fair Value | Level 2      
Financial assets:      
Promissory note receivable from Founders   0 0
Investments in unconsolidated affiliates 0 0 0
Estimated Fair Value | Level 2 | 2029 Convertible Notes      
Financial liabilities:      
Debt instruments, fair value 708,400 422,931 330,050
Estimated Fair Value | Level 2 | 2032 Senior Notes      
Financial liabilities:      
Debt instruments, fair value 315,000 320,734 316,406
Estimated Fair Value | Level 3      
Financial assets:      
Promissory note receivable from Founders   24,369 17,525
Investments in unconsolidated affiliates 1,598 1,156 850
Estimated Fair Value | Level 3 | 2029 Convertible Notes      
Financial liabilities:      
Debt instruments, fair value 0 0 0
Estimated Fair Value | Level 3 | 2032 Senior Notes      
Financial liabilities:      
Debt instruments, fair value $ 0 $ 0 $ 0