Earnings Per Share - Schedule of Earnings Per Share, Basic and Diluted (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended		9 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Earnings Per Share [Abstract]
Net income attributable to common stockholders	$ 377.9	$ 250.1	$ 600.1	$ 514.6
Less: Distributed and undistributed income available to participating securities, Basic			(0.1)	(0.1)
Distributed and undistributed income available to common stockholders, Basic	377.9	250.1	600.0	514.5
Less: Distributed and undistributed income available to participating securities, Diluted			(0.1)	(0.1)
Distributed and undistributed (loss) income available to common stockholders, Diluted	$ 377.9	$ 250.1	$ 600.0	$ 514.5
Basic weighted average shares outstanding	255.6	266.5	261.2	264.7
Effect of dilutive stock options and non- participating securities	1.8	2.5	2.0	2.3
Diluted weighted average shares outstanding	257.4	269.0	263.2	267.0
Basic earnings per share attributable to common stockholders	$ 1.48	$ 0.94	$ 2.30	$ 1.94
Diluted earnings per share attributable to common stockholders	$ 1.47	$ 0.93	$ 2.28	$ 1.93