Stock-Based Compensation (Tables)

12 Months Ended

Sep. 30, 2020

Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]

Schedule of Equity-Based Compensation Plans

Information related to the Company’s equity-based compensation plans in effect as of September 30, 2020 was as follows:

Plan Category	Number of Securities to be Issued Upon Exercise of Outstanding Options or Vesting of Share Awards		Weighted-Average Exercise Price of Outstanding Options		Number of Securities Remaining Available for Future Issuance Under Equity Compensation Plans
Equity compensation plans approved by security holders		1,731,277	$	74.38		4,039,917
Equity compensation plans not approved by security holders		—		—		—
		1,731,277	$	74.38		4,039,917

Schedule of Stock Based Compensation Expense

Total stock-based compensation expense (income) was as follows (in millions):

	Fiscal Year Ended September 30,
	2020			2019			2018
Stock options	$	6.8		$	6.9		$	6.6
Stock awards (shares and units)		15.8			15.0			13.7
Performance share awards		6.7			7.1			6.4
Cash-settled stock appreciation rights		0.2			0.4			(0.2	)
Cash-settled restricted stock unit awards		0.7			0.6			0.4
Total stock-based compensation cost		30.2			30.0			26.9
Income tax benefit recognized for stock-based compensation		(3.6	)		(4.9	)		(5.8	)
Stock-based compensation cost, net of tax	$	26.6		$	25.1		$	21.1

Schedule of Stock Option Activity

Stock Options — A summary of the Company’s stock option activity is as follows:

	Fiscal Year Ended September 30,
	2020					2019					2018
	Options			Weighted- Average Exercise Price		Options			Weighted- Average Exercise Price		Options			Weighted- Average Exercise Price
Outstanding, beginning of year		1,328,390		$	62.62		1,268,984		$	57.03		1,531,691		$	45.14
Granted		301,025			90.28		372,450			66.09		261,900			86.59
Forfeited		(40,965	)		79.00		(24,175	)		72.88		(43,270	)		66.49
Expired		(5,869	)		84.25		(8,721	)		76.92		(1	)		41.52
Exercised		(499,179	)		52.18		(280,148	)		40.62		(481,336	)		34.41
Outstanding, end of year		1,083,402			74.38		1,328,390			62.62		1,268,984			57.03
Exercisable, end of year		537,241			68.16		709,826			55.11		650,143			45.92

Schedule of Outstanding Stock Options

Stock options outstanding and exercisable as of September 30, 2020 were as follows (in millions, except share and per share amounts):

	Outstanding								Exercisable
Exercise Prices	Options		Weighted Average Remaining Contractual Life (in years)		Weighted Average Exercise Price		Aggregate Intrinsic Value		Options		Weighted Average Remaining Contractual Life (in years)		Weighted Average Exercise Price		Aggregate Intrinsic Value
$40.00 - $60.00		99,514		1.7	$	43.26	$	3.0		99,514		1.7	$	43.26	$	3.0
$60.01 - $80.00		493,958		6.2		66.41		3.5		282,819		4.7		66.64		1.9
$80.01 - $100.00		489,930		8.3		88.73		—		154,908		7.3		86.93		—
		1,083,402		6.7		74.38	$	6.5		537,241		4.9		68.16	$	4.9

Schedule of Weighted-Average Assumptions Used to Value Options

The Company uses the Black-Scholes valuation model to value stock options utilizing the following weighted-average assumptions:

	Fiscal Year Ended September 30,
Options Granted During	2020			2019			2018
Assumptions:
Expected term (in years)		5.4			5.4			5.4
Expected volatility		34.10	%		33.40	%		34.50	%
Risk-free interest rate		1.63	%		2.87	%		2.09	%
Expected dividend yield		1.37	%		1.50	%		1.15	%

Schedule of Nonvested Stock Activity

Stock Awards — A summary of the Company’s stock award activity is as follows:

	Fiscal Year Ended September 30,
	2020					2019					2018
	Number of  Shares			Weighted- Average Grant Date Fair Value		Number of  Shares			Weighted- Average Grant Date Fair Value		Number of  Shares			Weighted- Average Grant Date Fair Value
Nonvested, beginning of year		411,510		$	72.66		332,473		$	69.15		352,159		$	55.22
Granted		183,725			87.82		278,175			69.98		163,225			86.07
Forfeited		(27,076	)		80.57		(13,610	)		71.17		(26,915	)		65.66
Vested		(221,351	)		73.64		(185,528	)		62.47		(155,996	)		56.02
Nonvested, end of year		346,808			79.44		411,510			72.66		332,473			69.15

Schedule of Nonvested Performance-Based Units Activity

Performance Share Awards — A summary of the Company’s performance share awards activity is as follows:

	Fiscal Year Ended September 30,
	2020					2019					2018
	Number of  Shares			Weighted- Average Grant Date Fair Value		Number of  Shares			Weighted- Average Grant Date Fair Value		Number of  Shares			Weighted- Average Grant Date Fair Value
Nonvested, beginning of year		124,750		$	84.10		98,375		$	89.11		116,600		$	60.71
Granted		55,325			109.09		73,950			74.70		57,625			97.79
Forfeited		(16,615	)		92.88		(1,600	)		93.92		(13,977	)		71.75
Performance adjustments		33,941			87.44		31,768			71.43		57,914			47.50
Vested		(86,951	)		92.73		(77,743	)		76.12		(119,787	)		47.55
Nonvested, end of year		110,450			89.54		124,750			84.10		98,375			89.11

Schedule of Weighted-Average Assumptions to Estimate Grant Date Fair Values

The grant date fair values of the TSR performance share awards were estimated using a Monte Carlo simulation model utilizing the following weighted-average assumptions:

	Fiscal Year Ended September 30,
Total Shareholder Return Performance Shares Granted During	2020			2019			2018
Assumptions:
Expected term (in years)		2.87			2.86			2.86
Expected volatility		31.16	%		32.72	%		32.27	%
Risk-free interest rate		1.59	%		2.80	%		1.84	%