Stock-based Compensation (Tables)

3 Months Ended

Mar. 31, 2024

Share-Based Payment Arrangement [Abstract]

Compensation Cost and Related Tax Benefits

Compensation cost for the Company’s stock-based awards and the related tax benefits were as follows:

	Three Months Ended March 31,
(in millions)	2024			2023
Stock-based compensation expense	$	6.7		$	7.1
Tax benefit		(1.4	)		(1.5	)
Stock-based compensation expense, net of taxes	$	5.3		$	5.6

Summary of Stock Option Activity

Information on the Company’s stock option activity for the three months ended March 31, 2024 and 2023 is summarized below.

	Three Months Ended March 31,
	2024					2023
(in whole shares and dollars)	Shares			Weighted Average Exercise Price		Shares			Weighted Average Exercise Price
Outstanding, beginning of period		1,137,042		$	111.57		1,080,852		$	107.07
Granted		150,731			134.26		135,019			140.01
Exercised		(66,405	)		81.26		(36,286	)		96.03
Forfeited or cancelled		(2,277	)		134.26		(1,046	)		115.79
Outstanding, end of period		1,219,091			115.98		1,178,539			111.17

Summary of Activity Information about Employee Restricted Stock Units

The following tables summarize activity information about employee restricted stock units:

	Three Months Ended March 31,
	2024					2023
(in whole shares and dollars)	Shares			Weighted Average Grant Date Fair Value		Shares			Weighted Average Grant Date Fair Value
Time-based restricted stock units:
Outstanding, beginning of period		376,626		$	132.04		378,256		$	124.88
Granted		154,826			133.26		146,464			138.71
Vested		(118,768	)		115.43		(125,686	)		118.10
Forfeited		(7,370	)		131.90		(965	)		123.64
Outstanding, end of period		405,314			137.37		398,069			132.11
Performance-based and market-based restricted stock units:
Outstanding, beginning of period		120,504		$	132.76		119,163		$	122.81
Granted		53,336			132.27		50,115			137.90
Vested		(41,290	)		112.36		(44,781	)		114.14
Forfeited		(6,339	)		108.06		(3,803	)		109.07
Outstanding, end of period		126,211			140.47		120,694			132.73