XML 78 R32.htm IDEA: XBRL DOCUMENT v3.19.3.a.u2
Stockholders' Equity (Tables)
 12 Months Ended
Dec. 31, 2019
Stock-based Compensation Expense The stock-based compensation related to all of our stock-based awards and employee stock purchase plan for the year ended December 31, 2019, 2018 and 2017 is as follows (in thousands):
 
For the Year Ended December 31,
 
2019
 
2018
 
2017
Cost of net revenues
$
5,154

 
$
3,695

 
$
3,330

Selling, general and administrative
69,817

 
56,422

 
46,550

Research and development
13,213

 
10,646

 
8,974

Total stock-based compensation
$
88,184

 
$
70,763

 
$
58,854
Stock Option Activity

Fair value assumptions using the Monte Carlo simulation The following weighted-average assumptions used in the Monte Carlo simulation were as follows: 
 
Year Ended December 31,
 
2019
 
2018
 
2017
Expected term (in years)
3.0

 
3.0

 
3.0

Expected volatility
37.3
%
 
31.9
%
 
28.9
%
Risk-free interest rate
2.5
%
 
2.5
%
 
1.5
%
Expected dividends
—

 
—

 
—

Weighted average fair value per share at grant date
$
392.03

 
$
470.75

 
$
120.39
Schedule of ESPP share activity
The following table summarizes the ESPP shares issued:
 
Year Ended December 31,
 
2019
 
2018
 
2017
Number of shares issued (in thousands)
130

 
164

 
202

Weighted average price
$
136.73

 
$
96.95

 
$
59.93
Employee Stock Purchase Plan 2010  
Weighted Average Assumptions Used for the Fair Value of Options Component of Purchase Plan Granted Estimated at Grant Date
The fair value of the option component of the 2010 Purchase Plan shares was estimated at the grant date using the Black-Scholes option pricing model with the following weighted average assumptions:
 
Year Ended December 31,
  
2019
 
2018
 
2017
Expected term (in years)
1.4

 
1.3

 
1.2

Expected volatility
50.0
%
 
35.2
%
 
26.8
%
Risk-free interest rate
2.2
%
 
2.2
%
 
1.0
%
Expected dividends
—

 
—

 
—

Weighted average fair value at grant date
$
86.02

 
$
94.71

 
$
31.36
Stock Option  
Weighted Average Assumptions Used for the Fair Value of Options Component of Purchase Plan Granted Estimated at Grant Date

Restricted Stock Units (RSUs)  
Summary of Nonvested Shares A summary for the year ended December 31, 2019, is as follows:
 
Number of Shares
Underlying RSUs
(in thousands)
 
Weighted Average Grant Date Fair Value
 
Weighted Average
Remaining
Contractual Term
(in years)
 
Aggregate
Intrinsic Value
(in thousands)
Unvested as of December 31, 2018
931

 
$
129.42

 
 
 
 
Granted
292

 
255.42

 
 
 
 
Vested and released
(443
)
 
105.83

 
 
 
 
Forfeited
(84
)
 
184.04

 
 
 
 
Unvested as of December 31, 2019
696

 
$
190.60

 
1.1
 
$
194,114
Market Performance Based Restricted Stock Units  
Summary of Nonvested Shares
The following table summarizes the MSU performance for the year ended December 31, 2019:
 
Number of Shares
Underlying MSUs
(in thousands)
 
Weighted Average Grant Date Fair Value
 
Weighted Average
Remaining
Contractual Term
(in years)
 
Aggregate
Intrinsic Value
(in thousands)
Unvested as of December 31, 2018
324

 
$
215.07

 
 
 


Granted
138

 
240.73

 
 
 
 
Vested and released
(191
)
 
77.17

 
 
 
 
Forfeited
(27
)
 
271.96

 
 
 
 
Unvested as of December 31, 2019
244

 
$
331.35

 
1.1
 
$
68,055