Supporting Financial Information - Narrative (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Mar. 31, 2025	Mar. 31, 2024	Mar. 31, 2025	Mar. 31, 2024
Finite-Lived Intangible Assets [Line Items]
Amortization expense of intangible assets	$ 4.1	$ 4.1	$ 8.2	$ 8.2
Intangible assets, remaining amortization period	6 years 10 months 24 days		6 years 10 months 24 days
Depreciation	$ 0.2	$ 0.1	$ 0.3	$ 0.3
Customer contracts and related customer relationships
Finite-Lived Intangible Assets [Line Items]
Intangible assets, remaining amortization period	6 years 10 months 24 days		6 years 10 months 24 days
Backlog
Finite-Lived Intangible Assets [Line Items]
Intangible assets, remaining amortization period	6 years 10 months 24 days		6 years 10 months 24 days
Trade name
Finite-Lived Intangible Assets [Line Items]
Intangible assets, remaining amortization period	7 years 2 months 12 days		7 years 2 months 12 days
Covenants-not-to-compete
Finite-Lived Intangible Assets [Line Items]
Intangible assets, remaining amortization period	5 years 3 months 18 days		5 years 3 months 18 days