Stock-Based Compensation (Tables)

3 Months Ended

Mar. 31, 2020

Share-based Payment Arrangement [Abstract]

Stock Option Activity

The following table summarizes the Company’s stock option activity and related information for the 2011 Plan, the 2000 Plan and the Directors Plan for the three months ended March 31, 2020:

	Options	Weighted Average Exercise Price		Weighted Average Remaining Contractual Life	Aggregate Intrinsic value (in millions)
Outstanding at December 31, 2019	588,024	$	63.36	5.7	$	8.5
Granted	131,556	78.33
Exercised	(11,440)	37.84
Canceled	(3,531)	72.64
Outstanding at March 31, 2020	704,609	66.52		6.3	1.8
Exercisable at March 31, 2020	448,375	53.22		5.2	1.8

Share-Based Fair Value of Each Option Grant Weighted-Average Assumptions

The fair value of each option grant is estimated on the date of grant using the Black-Scholes option pricing model with the following weighted-average assumptions:

	Three Months Ended March 31,
	2020		2019
Dividend yield	0.60	%	0.66	%
Risk-free interest rate	1.56	%	2.63	%
Stock price volatility	27.9	%	25.8	%
Expected life (years)	5.0		5.0

Restricted Stock Activity and Incentive Stock Awards Activity

The following table summarizes the restricted stock activity and related information for the 2011 Plan, the 2000 Plan and the Directors Plan, and incentive stock units activity for the 2011 Plan and the 2000 Plan with related information for the three months ended March 31, 2020:

	Restricted Stock and Units	Incentive Stock Units	Weighted Average Grant Date Fair Value
Outstanding at December 31, 2019	791,031	572,002	$	73.64
Granted	189,734	238,277	78.34
Vested	(270,288)	(147,069)	76.89
Adjustment for incentive stock awards expected to vest	—	(6,744)	85.97
Canceled	(14,183)	(5,367)	69.45
Outstanding at March 31, 2020	696,294	651,099	74.12