Acquisitions - Schedule of Intangible Assets Assumed (Details) - USD ($) $ in Thousands		9 Months Ended
	Jan. 23, 2023	Jun. 30, 2024
Backlog
Acquired Finite-Lived Intangible Assets [Line Items]
Weighted-average Amortization Period (in years)		7 months 6 days
Trade names
Acquired Finite-Lived Intangible Assets [Line Items]
Weighted-average Amortization Period (in years)		1 year 8 months 12 days
Client relations
Acquired Finite-Lived Intangible Assets [Line Items]
Weighted-average Amortization Period (in years)		8 years 4 months 24 days
RPS Group PLC
Acquired Finite-Lived Intangible Assets [Line Items]
Fair Value	$ 174,094
Weighted-average Amortization Period (in years)	8 years 3 months 18 days
RPS Group PLC | Backlog
Acquired Finite-Lived Intangible Assets [Line Items]
Fair Value	$ 27,880
Weighted-average Amortization Period (in years)	1 year 7 months 6 days
RPS Group PLC | Trade names
Acquired Finite-Lived Intangible Assets [Line Items]
Fair Value	$ 27,260
Weighted-average Amortization Period (in years)	3 years
RPS Group PLC | Client relations
Acquired Finite-Lived Intangible Assets [Line Items]
Fair Value	$ 118,954
Weighted-average Amortization Period (in years)	11 years 1 month 6 days