Earnings Per Share (Tables)

6 Months Ended

Mar. 31, 2020

Earnings Per Share [Abstract]

Schedule of Earnings Per Share, Basic and Diluted

The following table sets forth the computation of basic and diluted earnings per share under the two-class method (in millions, except per share data):

	Three Months Ended					Six Months Ended
	March 31,					March 31,
	2020			2019		2020			2019
Numerator:
Net income attributable to common stockholders	$	148.1		$	160.4	$	286.6		$	299.5
Less: Distributed and undistributed income    available to participating securities		(0.1	)		—		(0.1	)		—
Distributed and undistributed income available to    common stockholders	$	148.0		$	160.4	$	286.5		$	299.5
Denominator:
Basic weighted average shares outstanding		259.0			256.6		258.6			255.7
Effect of dilutive stock options and non-    participating securities		1.2			2.8		1.5			3.7
Diluted weighted average shares outstanding		260.2			259.4		260.1			259.4
Basic earnings per share attributable to common    stockholders	$	0.57		$	0.63	$	1.11		$	1.17
Diluted earnings per share attributable to common    stockholders	$	0.57		$	0.62	$	1.10		$	1.15