Discontinued Operations, Goodwill and Intangible Assets - Schedule of Changes in Carrying Value of Goodwill by Reportable Segment (Details) $ in Thousands	12 Months Ended
	Sep. 30, 2025 USD ($)
Goodwill [Roll Forward]
Goodwill, beginning balance	$ 3,480,155
Foreign Exchange Impact	(5,000)
Acquired	225,400
Goodwill, ending balance	3,700,619
Americas
Goodwill [Roll Forward]
Goodwill, beginning balance	2,625,700
Foreign Exchange Impact	(5,400)
Acquired	150,100
Goodwill, ending balance	2,770,400
International
Goodwill [Roll Forward]
Goodwill, beginning balance	854,500
Foreign Exchange Impact	400
Acquired	75,300
Goodwill, ending balance	$ 930,200