Stock-Based Compensation (Tables)

3 Months Ended

Mar. 31, 2021

Stock-Based Compensation [Abstract]

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, 2020	3,202	$	143.01
Exercised	(70)	$	122.72
Forfeited/canceled	(7)	$	173.81
Outstanding at March 31, 2021	3,125	$	143.39	3.5	$	419,128
Exercisable at March 31, 2021	2,371	$	132.98	3.2	$	342,849
Unvested at March 31, 2021	754	$	176.21	4.7	$	76,279

Summary of Restricted Stock Unit and Performance Based Restricted Stock Unit Activity

	RSUs			PSUs
		Weighted-Average			Weighted-Average
	Number of	Grant Date Fair		Number of	Grant Date Fair
	Shares	Value per Share		Shares	Value per Share
	(in thousands)			(in thousands)
Outstanding at December 31, 2020 (1)	274	$	206.48	148	$	376.48
Granted (1)	101	$	235.92	153	$	236.48
Vested	(122)	$	185.34	—	$	—
Forfeited/canceled	(3)	$	224.37	(1)	$	376.50
Outstanding at March 31, 2021	250	$	228.47	300	$	304.80

(1)PSUs represent the target number of shares granted that are issuable at the end of the three year performance period. Fair value for a portion of the PSUs was calculated using a Monte Carlo simulation model.