Stock-based Compensation (Tables)

12 Months Ended

Sep. 30, 2020

Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]

Restricted Stock and Restricted Stock Unit Activity

Fiscal 2020 activity of restricted stock units subject to performance and/or market conditions is presented below:

	Units			Weighted Average Grant Date Fair Value Per Unit
Nonvested at September 30, 2019		263,910		$	73.20
Granted		91,662		$	76.19
Vested		(86,287	)	$	58.68
Forfeited		(9,341	)	$	79.34
Nonvested at September 30, 2020		259,944		$	78.92

Time-vested restricted stock and stock unit activity for fiscal 2020 is presented below:

	Shares/ Units			Weighted Average Grant Date Fair Value Per Share
Nonvested at September 30, 2019		96,277		$	72.83
Granted		33,350		$	76.13
Vested		(32,326	)	$	65.28
Forfeited		(3,628	)	$	76.94
Nonvested at September 30, 2020		93,673		$	76.45

Significant Assumptions Used in the Monte Carlo simulations

The significant assumptions used in the Monte Carlo simulations are as follows:

	2020		2019		2018
Risk-free interest rate	1.57%		2.88%		1.76%
Expected dividend yield of stock		—		—		—
Expected volatility of stock	16.8%		17.0%		16.0%
Vesting period	3.0 years		3.0 years		2.9 years

Compensation Cost Recognized for Share-based Compensation Arrangements

The amounts of compensation cost recognized for share-based compensation arrangements are presented below:

	2020			2019			2018
Total compensation cost	$	9.4		$	8.6		$	6.9
Compensation cost capitalized		(0.6	)		(1.4	)		(1.3	)
Prior period disallowed stock compensation capitalization		—			—			6.9
Compensation cost recognized in net income		8.8			7.2			12.5
Income tax benefit recognized in net income		(2.1	)		(1.7	)		(4.0	)
Compensation cost recognized in net income, net of income tax	$	6.7		$	5.5		$	8.5