Condensed Consolidated Statements of Comprehensive Income - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Statement of Comprehensive Income [Abstract]
Net income	$ 69.5	$ 49.1	$ 187.8	$ 154.8
Other comprehensive gain/(loss), net of tax:
Foreign currency translation adjustment	4.1	(5.4)	15.5	(5.5)
Cash flow hedges	2.6	(6.8)	31.6	(25.0)
Total other comprehensive gain/(loss), net of tax	6.7	(12.2)	47.1	(30.5)
Comprehensive income	$ 76.2	$ 36.9	$ 234.9	$ 124.3