Condensed Consolidated Statements of Comprehensive Income - USD ($) $ in Millions	3 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Statement of Comprehensive Income [Abstract]
Net income	$ 41.7	$ 19.5
Other comprehensive (loss)/income:
Foreign currency translation adjustment	(1.3)	13.9
Cash flow hedges	(0.1)	0.0
Other comprehensive (loss)/income	(1.4)	13.9
Comprehensive income	$ 40.3	$ 33.4