Stock-based Compensation (Tables)

3 Months Ended

Mar. 31, 2023

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)	2023			2022
Stock-based compensation expense	$	7.1		$	6.7
Tax benefit		(1.5	)		(1.4	)
Stock-based compensation expense, net of taxes	$	5.6		$	5.3

Summary of Stock Option Activity

Information on the Company’s stock option activity for the three months ended March 31, 2023 and 2022 is summarized below.

	Three Months Ended March 31,
	2023					2022
(in whole shares and dollars)	Shares			Weighted Average Exercise Price		Shares			Weighted Average Exercise Price
Outstanding, beginning of period		1,080,852		$	107.07		1,230,211		$	99.14
Granted		135,019			140.01		140,339			139.51
Exercised		(36,286	)		96.03		(192,400	)		81.48
Forfeited or cancelled		(1,046	)		115.79		(2,939	)		116.43
Outstanding, end of period		1,178,539			111.17		1,175,211			106.81

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,
	2023					2022
(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		378,256		$	124.88		380,100		$	117.60
Granted		146,464			138.71		143,208			138.20
Vested		(125,686	)		118.10		(114,978	)		119.35
Forfeited		(965	)		123.64		(5,609	)		119.92
Outstanding, end of period		398,069			132.11		402,721			124.40
Performance-based and market-based restricted stock units:
Outstanding, beginning of period		119,163		$	122.81		113,848		$	115.92
Granted		50,115			137.90		47,954			140.36
Vested		(44,781	)		114.14		(39,338	)		124.42
Forfeited		(3,803	)		109.07		(2,936	)		121.73
Outstanding, end of period		120,694			132.73		119,528			122.78