Stock-based Compensation (Tables)

6 Months Ended

Jun. 30, 2021

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

	Three Months Ended June 30,						Six Months Ended June 30,
(in millions)	2021			2020			2021			2020
Stock-based compensation expense	$	5.4		$	4.5		$	11.0		$	9.5
Tax benefit		(1.1	)		(0.9	)		(2.3	)		(2.0	)
Stock-based compensation expense, net of taxes	$	4.3		$	3.6		$	8.7		$	7.5

Information on the Company’s stock option activity for the six months ended June 30, 2021 and 2020 is summarized below.

	Six Months Ended June 30,
	2021					2020
(in whole shares and dollars)	Shares			Weighted Average Exercise Price		Shares			Weighted Average Exercise Price
Outstanding, beginning of period		1,282,278		$	93.64		1,121,559		$	87.88
Granted		178,040			115.35		242,598			118.34
Exercised		(155,584	)		82.43		(40,889	)		77.86
Forfeited or cancelled		(4,769	)		118.01		(21,862	)		111.65
Outstanding, end of period		1,299,965			97.87		1,301,406			93.47

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

	Six Months Ended June 30,
	2021					2020
(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		350,480		$	116.37		335,166		$	109.55
Granted		170,473			115.32		142,412			117.72
Vested		(114,274	)		110.81		(85,880	)		91.98
Forfeited		(15,765	)		117.01		(17,004	)		116.00
Outstanding, end of period		390,914			117.52		374,694			116.39
Performance-based and market-based restricted stock units:
Outstanding, beginning of period		97,043		$	119.59		86,252		$	110.70
Granted		62,143			114.66		54,415			105.10
Vested		(43,506	)		122.27		(40,601	)		80.92
Forfeited		(1,832	)		116.90		(3,023	)		124.78
Outstanding, end of period		113,848			115.92		97,043			119.59