Joint Ventures and Variable Interest Entities - Schedule of Equity in Earnings of Unconsolidated Joint Ventures (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2023
Joint Ventures and Variable Interest Entities [Line Items]
Total	$ 27,013	$ 2,124	$ (279,352)
Unconsolidated Joint Ventures
Joint Ventures and Variable Interest Entities [Line Items]
Total	27,000	2,100	(279,400)
Unconsolidated Joint Ventures | Pass-through joint ventures
Joint Ventures and Variable Interest Entities [Line Items]
Total	27,600	29,000	24,500
Unconsolidated Joint Ventures | Other joint ventures
Joint Ventures and Variable Interest Entities [Line Items]
Total	$ (600)	$ (26,900)	$ (303,900)