Share-Based Compensation (Tables)

3 Months Ended

Mar. 31, 2019

Disclosure of Compensation Related Costs, Share-based Payments [Abstract]

Schedule of weighted averages of the assumptions used in estimating the fair value of stock option awards

The weighted averages of the valuation assumptions used to determine the fair value of each option award on the date of grant and the weighted average estimated fair values were as follows:  

	For the Three Months Ended March 31,
	2019			2018
Share price at grant	$	206.94		$	178.26
Expected stock price volatility	26		%	24		%
Expected term, in years	6.0			5.8
Risk-free interest rate	2.5		%	2.7		%
Weighted average fair value of options granted	$	63.55		$	52.49