Acquisitions - Schedule of Recognized Identified Assets Acquired and Liabilities Assumed - Plex (Details) - USD ($) $ in Millions	Aug. 31, 2021	Jun. 30, 2022	Sep. 30, 2021
Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Net [Abstract]
Goodwill		$ 3,582.2	$ 3,625.9
Plex Systems
Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Net [Abstract]
Accounts receivable	$ 14.8
All other assets	28.4
Goodwill	1,728.2
Intangible assets	531.4
Total assets acquired	2,302.8
Less: Contract liabilities	(29.2)
Less: Other liabilities assumed	(32.8)
Less: Deferred income taxes	(35.3)
Net assets acquired, excluding cash	2,205.5
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net [Abstract]
Total purchase consideration, net of cash acquired	$ 2,205.5