Stock-Based Compensation (Tables)

6 Months Ended

Jun. 30, 2019

Stock-Based Compensation [Abstract]

Schedule of Assumptions Used to Estimate Fair Value of Stock Options

	For the six months ended
	June 30,
	2019	2018
Risk free interest rate	1.84% - 2.47%	2.57% - 2.87%
Dividend yield	1.3%	0.7%
Expected volatility	20%	22%
Expected lives	4.6 years	4.6 years

Summary of Stock Option Activity

		Weighted-		Weighted-Average
		Average		Remaining
	Number	Exercise Price		Contractual	Aggregate
	of Shares	Per Share		Life (in years)	Intrinsic Value
Outstanding at December 31, 2018	4,816	$	114.48
Granted	1,059	$	182.90
Exercised	(1,088)	$	100.70
Forfeited/canceled	(49)	$	136.33
Outstanding at June 30, 2019	4,738	$	132.72	4.6	$	436,326
Exercisable at June 30, 2019	2,144	$	110.19	3.3	$	245,862
Unvested at June 30, 2019	2,594	$	151.36	5.6	$	190,464

Summary of Restricted Stock Unit Activity

		Weighted-Average
	Number of	Grant Date Fair
	Shares	Value per Share
	(in thousands)
Outstanding at December 31, 2018	324	$	128.69
Granted	131	$	182.30
Vested	(129)	$	125.39
Forfeited/canceled	(10)	$	147.12
Outstanding at June 30, 2019	316	$	152.22