Earnings Per Common Share (Tables)

6 Months Ended

Mar. 31, 2020

Earnings Per Share [Abstract]

Schedule of Basic and Diluted Earnings Per Share

	Three Months Ended March 31,				Six Months Ended March 31,
	2020		2019		2020		2019
Basic Earnings Per Common Share:
Net Income	$	133.6	$	154.6	$	200.6	$	221.9
Less: Provision for preferred dividends		3.7		—		7.4		—
Income allocated to participating securities		0.2		0.3		0.3		0.5
Income Available to Common Shareholders	$	129.7	$	154.3	$	192.9	$	221.4
Weighted Average Common Shares Outstanding (in millions)		51.0		50.6		51.0		50.6
Basic Earnings Per Common Share	$	2.55	$	3.05	$	3.78	$	4.37
Diluted Earnings Per Common Share:
Net Income	$	133.6	$	154.6	$	200.6	$	221.9
Less: Provision for preferred dividends		3.7		—		7.4		—
Income allocated to participating securities		0.2		0.3		0.3		0.5
Income Available to Common Shareholders	$	129.7	$	154.3	$	192.9	$	221.4
Weighted Average Common Shares Outstanding (in millions)		51.0		50.6		51.0		50.6
Dilutive Effect of Restricted Stock and Restricted Stock Units (in millions)*		0.1		0.2		0.1		0.2
Weighted Average Diluted Common Shares (in millions)		51.1		50.8		51.1		50.8
Diluted Earnings Per Common Share	$	2.54	$	3.04	$	3.77	$	4.36
* Calculation excludes certain outstanding common shares (shown in millions by    period at the right) attributable to stock units subject to performance or market    conditions and restricted stock, which could have a dilutive effect in the future		0.1		0.3		0.1		0.3