Discontinued Operations, Goodwill and Intangible Assets - Schedule of Gross Amount and Accumulated Amortization of Acquired Identifiable Intangible Assets with Finite Useful Lives (Details) - USD ($) $ in Thousands	Sep. 30, 2025	Sep. 30, 2024
Discontinued Operations, Goodwill and Intangible Assets
Gross Amount	$ 185,800	$ 671,700
Accumulated Amortization	(2,500)	(664,800)
Total	183,284	6,932
Backlog and Customer relationships
Discontinued Operations, Goodwill and Intangible Assets
Gross Amount	7,400	671,700
Accumulated Amortization	(2,500)	(664,800)
Total	$ 4,900	6,900
Backlog and Customer relationships | Minimum
Discontinued Operations, Goodwill and Intangible Assets
Amortization Period (in years)	1 year
Backlog and Customer relationships | Maximum
Discontinued Operations, Goodwill and Intangible Assets
Amortization Period (in years)	11 years
Intellectual property
Discontinued Operations, Goodwill and Intangible Assets
Gross Amount	$ 178,400	0
Accumulated Amortization	0	0
Total	$ 178,400	$ 0
Amortization Period (in years)	5 years