Stock-based Compensation (Tables)

12 Months Ended

Sep. 30, 2021

Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]

Restricted Stock and Restricted Stock Unit Activity

Fiscal 2021 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, 2020		259,944		$	78.92
Granted		133,726		$	68.69
Vested		(55,619	)	$	80.06
Forfeited		(25,455	)	$	72.98
Nonvested at September 30, 2021		312,596		$	74.33

Time-vested restricted stock and stock unit activity for fiscal 2021 is presented below:

	Shares/ Units			Weighted Average Grant Date Fair Value Per Share
Nonvested at September 30, 2020		93,673		$	76.45
Granted		48,340		$	64.29
Vested		(30,313	)	$	77.15
Forfeited		(1,400	)	$	72.70
Nonvested at September 30, 2021		110,300		$	70.98

Significant Assumptions Used in the Monte Carlo simulations

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

	2021		2020		2019
Risk-free interest rate	0.22%		1.57%		2.88%
Expected dividend yield of stock		—		—		—
Expected volatility of stock	31.4%		16.8%		17.0%
Vesting period	3.0 years		3.0 years		3.0 years

Compensation Cost Recognized for Share-based Compensation Arrangements

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

	2021			2020			2019
Total compensation cost	$	16.6		$	9.4		$	8.6
Compensation cost capitalized		(2.7	)		(0.6	)		(1.4	)
Compensation cost recognized in net income		13.9			8.8			7.2
Income tax benefit recognized in net income		(3.2	)		(2.1	)		(1.7	)
Compensation cost recognized in net income, net of income tax	$	10.7		$	6.7		$	5.5