Share-Based Compensation (Tables)

6 Months Ended

Mar. 31, 2022

Share-based Payment Arrangement [Abstract]

Schedule of Recognized Share-Based Compensation Cost

Share-based compensation cost recognized on the consolidated income statements is summarized below:

	Three Months Ended		Six Months Ended
	31 March		31 March
	2022	2021	2022	2021
Before-tax share-based compensation cost	$10.5	$12.9	$27.3	$22.4
Income tax benefit	(2.6)	(3.1)	(6.7)	(5.4)
After-tax share-based compensation cost	$7.9	$9.8	$20.6	$17.0

Schedule of Assumptions for Fair Value of Market-Based Deferred Stock Units

The calculation of the fair value of market-based deferred stock units used the following assumptions:

Expected volatility	30.5	%
Risk-free interest rate	0.8	%
Expected dividend yield	2.1	%