Share-based Compensation (Tables)

9 Months Ended

Sep. 30, 2021

Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]

Summary of Stock Option Activity

The following table summarizes the Company’s stock option activity (in thousands, except per share data and years) for the three months ended September 30, 2021:

	Stock Options Outstanding
				Weighted Average		Aggregate		Weighted Average
				Exercise Price		Intrinsic		Remaining Contractual
	Shares			Per Share		Value		Term (Years)
Balance as of July 1, 2021		1,280		$	260.71
Granted		5		$	615.57
Exercised		(50	)	$	144.64	$	27,633
Forfeited/Expired		(5	)	$	730.42
Balance as of September 30, 2021		1,230		$	265.00
Exercisable as of September 30, 2021		552		$	131.41	$	246,831		3.4
Expected to vest as of September 30, 2021		678		$	373.86	$	168,911		8.6
Total		1,230		$	265.00	$	415,742		6.3

Schedule of Range of Exercise Prices per Share

Stock options outstanding as of September 30, 2021 are comprised of the following range of exercise prices per share (in thousands, except per share data and years):

	Stock Options Outstanding at September 30, 2021
			Weighted Average		Weighted Average
			Exercise Price		Remaining Contractual
Range of Exercise Prices per Share	Shares		Per Share		Term (Years)
$121.43 - $200.00		938	$	137.41		5.3
$400.01 - $500.00		20	$	470.00		9.7
$600.01 - $691.23		272	$	689.84		9.4
Total		1,230	$	265.00		6.3

Assumptions Used in Black-Scholes Pricing Model

The weighted average grant date fair value of stock option awards using the Black-Scholes pricing model was $334.40 and $48.20 for each share subject to a stock option granted during the three months ended September 30, 2021 and 2020, respectively, based on the following assumptions:

	Three months ended
	September 30,
	2021			2020
Expected term of options in years	6.3				6.3
Expected volatility		57.6	%		33.6% - 33.7%
Risk-free interest rate		1.0	%		0.3% - 0.4%
Expected dividend yield		0.0	%			0.0	%

Summary of Restricted Stock Unit Activity

As of September 30, 2021, there were 112,746 restricted stock units outstanding under the 2013 Equity Plan, which the Company intends to settle in shares.  The following table summarizes the Company’s restricted stock unit activity (in thousands) for the periods indicated:            

	Restricted Stock Units Outstanding
				Aggregate
				Intrinsic
	Units			Value
Balance as of July 1, 2021		86
Granted		28
Vested		0		$	0
Forfeited		(1	)
Balance as of September 30, 2021		113
Expected to vest as of September 30, 2021		113		$	65,212